2. SOLIDS
• Solids are figures having the three
dimensions of length, width, and depth
bounded by plane surfaces. Solids may
also be known as polyhedra. The plane
surfaces of polyhedra are called faces and if
the faces are regular polygons, the solids
are regular polyhedra.
6. Platonic solid
• Any of the five regular polyhedrons – solids with regular
polygon faces and the same number of faces meeting at
each corner – that are possible in three dimensions. They
are the tetrahedron (a pyramid with triangular faces), the
octahedron (an eight-sided figure with triangular faces),
the dodecahedron (a 12-sided figure with pentagonal
faces), the icosahedron (a 20-sided figure with triangular
faces), and the hexahedron or cube. They are named after
Plato who described them in one of his books, though it
was Euclid who proved that there are only five regular
polyhedra. A regular solid with hexagonal faces cannot
exist because if it did, the sum of the angles of any three
hexagonal corners that meet would already equal 360°, so
such an object would be planar.
11. Platonic solid
• Each of these solids possesses an inscribed and a
circumscribed sphere, which has the same center O.
Further, the mid-points of all the edges of a Platonic solid
also lie on a sphere again with center O. If we construct the
inscribed sphere of a Platonic solid and join neighboring
points of contact of the sphere with the faces of the
polyhedron, there results within the sphere another regular
polyhedron, which has the same number of vertices as the
original solid has faces, and the same number of edges as
the original solid. The cube yields an octahedron, the
icosahedron a dodecahedron, and the tetrahedron another
tetrahedron.
12. PRISMS
• A prism is a solid with two bases (top and
bottom) that are equal regular polygons and
three or more lateral faces that are
parallelograms. If the bases are also
parallelograms, the prism is
a parallelepiped. A right prism has faces
and lateral edges that are perpendicular to
the bases. Oblique prisms have faces and
lateral edges oblique to the bases.
15. PYRAMIDS
• Pyramids have polygons for a base and triangular
lateral faces that intersect at the vertex or top of
the pyramid. A centerline from the vertex to the
center of the base is known as the axis and its
height is called the altitude. If the axis is
perpendicular to the base, the pyramid is a right
pyramid. All other pyramids are oblique
pyramids. A pyramid that has been cut off near
the vertex oblique to the base is said to
be truncated; if the pyramid is cut off parallel to
the base, the cut plane is known as a frustum
19. CYLINDERS
• Cylinders are two parallel bases formed by a fixed curve
or directrix revolving around a straight line or generatrix
at the center. The generatrix at the center of the cylinder
is also called an axis. The height of the cylinder is called
the altitude. Any point along the edges of the cylinder is
referred to as an element. Right circular cylinders have
lateral edges perpendicular to the bases and oblique
circular cylinders have lateral edges oblique to the bases.
Moving a point around and along the surface of a cylinder
with uniform angular velocity to the axis and with a
uniform linear velocity in the direction of the axis produces
a helix. You may construct a helix using a cylinder or cone
21. CONES
• Cones have a generatrix that terminates in a fixed point at a vertex
around which revolves a directrix or closed curve base. The
generatrix is also known as the axis whose height is referred to as
altitude. Any point around the cone from the base to the vertex is
called an element. A cone whose axis is perpendicular to its base is
a right cone.
• Planes intersecting a cone will make the cone appear truncated or
frustum. Planes intersecting a right cone
produce conic sections. Conic sections appear as curves.
• A conic section perpendicular to the axis appears as a circle at the
plane of intersection. A conic section with a cutting plane oblique to
the axis but making a greater angle with the axis than the elements
appears as an ellipse.
• When the plane of intersection is oblique to the axis and at the same
angle to the axis as the elements, the curves is referred to as
a parabola. An oblique plane of intersection that makes a smaller
angle to the axis than the elements is known as a hyperbola. Cones
may also be used to construct helixes.
23. SPHERES
• Spheres are formed by a circle revolving
around its diameter. The diameter of the
circle then becomes the axis and the ends of
the axis are known as poles
25. Tips for projection of solids
• When the axis of the solid inclined any of the projection plane,
• First assume the axis is perpendicular to that plane.
• Draw the projection in simple position
– Top view first if the axis is perpendicular to HP
Front view first if the axis is perpendicular to VP
• Change position of the view to the given inclination
– Tilt the front view, if the axis inclined to the HP
Tilt the top view, if the axis inclined to the VP
• Project from this view to get the final view
– Project from the front view, to get the top view if the axis inclined to the HP
Project from the top view, to get the front view if the axis inclined to the VP
• Ensure all the points are named in an appropriate manner
– Lower case letters with a (‘)dash for the front views
– Lower case letters alone for the top views
26. SINGLE POINT PERSPECTIVE
Single-point perspective is just about the
simplest form of perspective projection it
is possible to have. It is called single-point
perspective because it involves only a
single vanishing point.
The vanishing point is a technique in
perspective drawing. The simplest use of
the vanishing point is the one point
perspective
Perspective is a realistic way of drawing
objects in 3D.
27. SINGLE POINT PERSPECTIVE -
VANISHING POINTS
Altering the position of the VP changes the
view of the object being drawn. For
example, to look down at the top of the
object the vanishing point must be above.
29. SINGLE POINT
PERSPECTIVE -
VANISHING POINTS
Moving the VP to the left or right of the
object will allow the sides to be seen. If
the VP is placed directly behind the object
then only the front will be seen.
30. SINGLE POINT PERSPECTIVE DRAWING -
EXERCISE
Draw your name in a decorative /
imaginative style. Place a single vanishing
point above, in the centre. Apply
appropriate colour and shade. See the
example below
31. DRAWING A TABLE IN
SINGLE POINT PERSPECTIVE
A three dimensional view of a traditional
wood kitchen table is seen below. Draw
the table or a similar one in single point
perspective.
32. DRAWING A TABLE IN
SINGLE POINT PERSPECTIVE
1. Draw a side of the table and the
position of the vanishing point.
Positioning the vanishing point high on
the left or right hand side means that one
side of the table will be seen when the
drawing of the table is completed.
33. DRAWING A TABLE IN
SINGLE POINT PERSPECTIVE
2. Starting with the table top, project
guidelines back to the vanishing point and
complete drawing the top.
Then project more guidelines for each of the
front legs, adding thickness to each one.
34. DRAWING A TABLE IN
SINGLE POINT PERSPECTIVE
The most difficult part is ensuring that the
back legs line up with the front legs. One
way of ensuring that this happens is to
project faint lines as shown on the drawing
below.
35. DRAWING A TABLE IN
SINGLE POINT PERSPECTIVE
Add suitable color /shade using a colored
pencils.
Include wood grain to the top of the table.
36. TWO POINT PERSPECTIVE
A graphical technique in which a three-dimensional
object is represented in two dimensions, and in which
parallel lines in two of its dimensions are shown to
converge towards two vanishing points
37. TWO POINT PERSPECTIVE
The cube apposite is drawn with two
vanishing points and as a result the sides
look as if they are slowly fading away into
the distance. Two vanishing points gives
this 'feel' to a drawing.
38. TWO POINT PERSPECTIVE
Mark two vanishing points on the paper and faintly draw a line between
them - this is called the horizon line. Then draw one side/edge of the
cube beneath the horizon line and in the centre between the vanishing
points.
44. In this example a simple kitchen table is
drawn in two point perspective. This is
much more difficult compared to the
single point perspective shown earlier.
This time it is very important to project
guidelines towards both vanishing points.
TWO POINT PERSPECTIVE
49. EXAMPLE - EXTERNAL
VIEW OF BUNGALOW -1
Below is an example of a bungalow drawn in two point perspective. Appropriate
colour and shade have been added.
Hint - Always make your drawing / design a little different. In the drawing below
clothes are hanging on a washing line and a door is open giving a view inside. Use
your imagination and make your design stand out by adding individual touches.
50. EXAMPLE - EXTERNAL
VIEW OF BUNGALOW - 2
Below is an example of a bungalow drawn in two point perspective. Appropriate
colour and shade have been added.
Hint - Always make your drawing / design a little different. In the drawing below a
pond has been added and a range of plants and trees. Plus, other houses are drawn
in the distance.. Use your imagination and make your design stand out by adding
individual touches.
51. EXAMPLE - EXTERNAL
VIEW OF BUNGALOW - 3
Below is an example of a bungalow drawn in two point perspective. Appropriate
colour and shade have been added.
Hint - Always make your drawing / design a little different. In the drawing below
the interior of rooms can be seen through the windows. Also, a neat garden has
been drawn at the front of the house. Use your imagination and make your design
stand out by adding individual touches.
52. ESTIMATED PERSPECTIVE
Sometimes, in order to produce a realistic drawing the vanishing points need
to be positioned beyond the edge of the paper. This is estimated perspective.
When drawing, the guidelines they are projected back to imaginary vanishing
points. Estimated perspective allows objects to be drawn close up and yet
still look as if drawn in perspective.
53. OBLIQUE PROJECTION
Oblique projection is a method of drawing objects in 3 dimensions. It is quite a
simple technique compared to isometric or even perspective drawing. However, to
draw accurately in oblique projection traditional drawing equipment is needed (see
diagram below).
54. OBLIQUE PROJECTION
The technique for drawing a cube in oblique projection is outlined below,
stage by stage. To draw it correctly in oblique projection three main rules
must be followed:
1. Draw the front or side view of the object.
2. All measurements drawn backwards are half the original measurement.
3. 45 degrees is the angle for all lines drawn backwards
56. OBLIQUE PROJECTION
Draw 45 degree lines from each corner of the square. The distance of any
lines drawn back at 45 degrees should be halved. For example, a cube may
have sides of 100mm but they must be drawn 50mm in length. This should
mean that the cube will look more realistic and in proportion.
57. OBLIQUE PROJECTION
Draw 45 degree lines from each corner of the square. The distance of any
lines drawn back at 45 degrees should be halved. For example, a cube
may have sides of 100mm but they must be drawn 50mm in length. This
should mean that the cube will look more realistic and in proportion.
58. STEPS TO SOLVE PROBLEMS IN SOLIDS
Problem is solved in three steps:
STEP 1: ASSUME SOLID STANDING ON THE PLANE WITH WHICH IT IS MAKING INCLINATION.
( IF IT IS INCLINED TO HP, ASSUME IT STANDING ON HP)
( IF IT IS INCLINED TO VP, ASSUME IT STANDING ON VP)
IF STANDING ON HP - IT’S TV WILL BE TRUE SHAPE OF IT’S BASE OR TOP:
IF STANDING ON VP - IT’S FV WILL BE TRUE SHAPE OF IT’S BASE OR TOP.
BEGIN WITH THIS VIEW:
IT’S OTHER VIEW WILL BE A RECTANGLE ( IF SOLID IS CYLINDER OR ONE OF THE PRISMS):
IT’S OTHER VIEW WILL BE A TRIANGLE ( IF SOLID IS CONE OR ONE OF THE PYRAMIDS):
DRAW FV & TV OF THAT SOLID IN STANDING POSITION:
STEP 2: CONSIDERING SOLID’S INCLINATION ( AXIS POSITION ) DRAW IT’S FV & TV.
STEP 3: IN LAST STEP, CONSIDERING REMAINING INCLINATION, DRAW IT’S FINAL FV & TV.
AXIS
VERTICAL
AXIS
INCLINED HP
AXIS
INCLINED VP
AXIS
VERTICAL
AXIS
INCLINED HP
AXIS
INCLINED VP
AXIS TO VP
er AXIS
INCLINED
VP
AXIS
INCLINED HP
AXIS TO VP
er AXIS
INCLINED
VP
AXIS
INCLINED HP
GENERAL PATTERN ( THREE STEPS ) OF SOLUTION:
GROUP B SOLID.
CONE
GROUPA SOLID.
CYLINDER
GROUP B SOLID.
CONE
GROUPA SOLID.
CYLINDER
Three steps
If solid is inclined to Hp
Three steps
If solid is inclined to Hp
Three steps
If solid is inclined to Vp
Study Next Problems and Practice them separately !!
Three steps
If solid is inclined to Vp
59. PROBLEM
• A right regular pentagonal pyramid, side of
base 25mm and height 50 mm, lies on HP
on one of its slant edges and has its axis
parallel to V.P. Draw its projections.
60.
61. PROBLEM
• A right circular cone, diameter of base
50mm and axis 62mm long, rests on its base
rim on HP with its axis parallel to VP and
one of the elements perpendicular to HP.
Draw the projections of cone.
62.
63. PROBLEM
• A right circular cone, diameter of base
50mm and height 62mm, lies on HP on one
of its elements, with its axis parallel to VP.
Draw the projections of cone.
64.
65. PROBLEM
• A right circular cone, diameter of base
35mm and height 40mm, rests on an
auxiliary horizontal plane on its base rim,
such that its axis is parallel to the V.P and
inclined at 45 degrees to the HP. Draw its
projections using third angle projection
method.
66.
67. PROBLEM
• A right circular cylinder, diameter of base
50mm and height 70mm, rests on ground
plane such that its axis is parallel to VP and
inclined to HP at 45 degrees. Draw its
projections.
68.
69. PROBLEM
• A right circular cylinder, diameter of base
40mm and height 60mm, is resting in HP on
its base rim such that its axis is parallel to
VP, inclined at 30 degrees to th eHP and is
40mm away from the VP. Draw its
projections when it is in first quadrant,
(i) by change of position of the reference
line (ii) by change of position of cylinder
70.
71. PROBLEM
• An ash tray, made of thin sheet of steel, is
spherical in shape with flat, circular top of
68mm diameter and bottom of 52mm
diameter and parallel to each other. The
greatest diameter of it is 100mm. Draw the
projections of the ash tray when its axis is
parallel to VP and (i) makes an angle of 60
degrees with the HP (ii) its base is inclined
at 30 degrees to the HP.
74. DEVELOPMENT OF SURFACES OF SOLIDS.
MEANING:-
ASSUME OBJECT HOLLOW AND MADE-UP OF THIN SHEET. CUT OPEN IT FROM ONE SIDE AND
UNFOLD THE SHEET COMPLETELY. THEN THE SHAPE OF THAT UNFOLDED SHEET IS CALLED
DEVELOPMENT OF LATERLAL SUEFACES OF THAT OBJECT OR SOLID.
LATERLAL SURFACE IS THE SURFACE EXCLUDING SOLID’S TOP & BASE.
ENGINEERING APLICATION:
THERE ARE SO MANY PRODUCTS OR OBJECTS WHICH ARE DIFFICULT TO MANUFACTURE BY
CONVENTIONAL MANUFACTURING PROCESSES, BECAUSE OF THEIR SHAPES AND SIZES.
THOSE ARE FABRICATED IN SHEET METAL INDUSTRY BY USING
DEVELOPMENT TECHNIQUE. THERE IS A VAST RANGE OF SUCH OBJECTS.
EXAMPLES:-
Boiler Shells & chimneys, Pressure Vessels, Shovels, Trays, Boxes & Cartons, Feeding Hoppers,
Large Pipe sections, Body & Parts of automotives, Ships, Aeroplanes and many more.
WHAT IS
OUR OBJECTIVE
IN THIS TOPIC ?
To learn methods of development of surfaces of
different solids, their sections and frustums.
1. Development is different drawing than PROJECTIONS.
2. It is a shape showing AREA, means it’s a 2-D plain drawing.
3. Hence all dimensions of it must be TRUE dimensions.
4. As it is representing shape of an un-folded sheet, no edges can remain hidden
And hence DOTTED LINES are never shown on development.
But before going ahead,
note following
Important points.
Study illustrations given on next slides carefully.
75. D
H
D
S
S
H
= R
L
3600
R=Base circle radius.
L=Slant height.
L= Slant edge.
S = Edge of base
H= Height S = Edge of base
H= Height D= base diameter
Development of lateral surfaces of different solids.
(Lateral surface is the surface excluding top & base)
Prisms: No.of Rectangles
Cylinder: A Rectangle
Cone: (Sector of circle) Pyramids: (No.of triangles)
Tetrahedron: Four Equilateral Triangles
All sides
equal in length
Cube: Six Squares.
80. X Y
X1
Y1
A
B
C
E
D
a
e
d
b
c
A B C D E A
DEVELOPMENT
a”
b”
c”
d”
e”
Problem 1: A pentagonal prism , 30 mm base side & 50 mm axis
is standing on Hp on it’s base whose one side is perpendicular to Vp.
It is cut by a section plane 450 inclined to Hp, through mid point of axis.
Draw Fv, sec.Tv & sec. Side view. Also draw true shape of section and
Development of surface of remaining solid.
Solution Steps:for sectional views:
Draw three views of standing prism.
Locate sec.plane in Fv as described.
Project points where edges are getting
Cut on Tv & Sv as shown in illustration.
Join those points in sequence and show
Section lines in it.
Make remaining part of solid dark.
For True Shape:
Draw x1y1 // to sec. plane
Draw projectors on it from
cut points.
Mark distances of points
of Sectioned part from Tv,
on above projectors from
x1y1 and join in sequence.
Draw section lines in it.
It is required true shape.
For Development:
Draw development of entire solid. Name from
cut-open edge I.e. A. in sequence as shown.
Mark the cut points on respective edges.
Join them in sequence in st. lines.
Make existing parts dev.dark.
81. PROBLEM
• Develop the lateral surface of a right regular
hexagonal prism of 20mm base edge and
50mm height.
82.
83. PROBLEM
• A right regular pentagonal prism, edge of
base 20mm and height 50mm, rests on its
base with one of its base edges
perpendicular to VP. An AIP inclined to HP
at 30 degrees and perpendicular to th eVP
cuts its axis at a distance of 30mm from the
base. Develop the lateral surface of the
truncated prism.
84.
85. PROBLEM
• A right regular pentagonal prism, edge of
base 30mm and height 75mm, resting on its
base on HP, is cut by a section plane
inclined to HP at 45 degrees and meeting
the axis at a distance of 18mm from its top
end. Develop the outside surface of the cut
prism.
86.
87. PROBLEM
• A right regular pentagonal prism, edge of
base 30mm and height 75mm, rests on its
base on HP. It is truncated from both of its
ends by section planes develop the lateral
surface of the truncated prism.
90. INTERSECTION OF SOLIDS
WHEN ONE SOLID PENETRATES ANOTHER SOLID THEN THEIR SURFACES INTERSECT
AND
AT THE JUNCTION OF INTERSECTION A TYPICAL CURVE IS FORMED,
WHICH REMAINS COMMON TO BOTH SOLIDS.
THIS CURVE IS CALLED CURVE OF INTERSECTION
AND
IT IS A RESULT OF INTERPENETRATION OF SOLIDS.
PURPOSE OF DRAWING THESE CURVES:-
WHEN TWO OBJECTS ARE TO BE JOINED TOGATHER, MAXIMUM SURFACE CONTACT BETWEEN BOTH
BECOMES A BASIC REQUIREMENT FOR STRONGEST & LEAK-PROOF JOINT.
Curves of Intersections being common to both Intersecting solids,
show exact & maximum surface contact of both solids.
Study Following Illustrations Carefully.
Square Pipes. Circular Pipes. Square Pipes. Circular Pipes.
Minimum Surface Contact.
( Point Contact) (Maximum Surface Contact)
Lines of Intersections. Curves of Intersections.
91. A machine component having
two intersecting cylindrical
surfaces with the axis at
acute angle to each other.
Intersection of a Cylindrical
main and Branch Pipe.
Pump lid having shape of a
hexagonal Prism and
Hemi-sphere intersecting
each other.
Forged End of a
Connecting Rod.
A Feeding Hopper
In industry.
An Industrial Dust collector.
Intersection of two cylinders.
Two Cylindrical
surfaces.
SOME ACTUAL OBJECTS ARE SHOWN, SHOWING CURVES OF INTERSECTIONS.
BY WHITE ARROWS.
92. REFFER ILLUSTRATIONS
AND
NOTE THE COMMON
CONSTRUCTION
FOR ALL
THE CASES
1.CYLINDER TO CYLINDER2.
2.SQ.PRISM TO CYLINDER
3.CONE TO CYLINDER
4.TRIANGULAR PRISM TO CYLNDER
5.SQ.PRISM TO SQ.PRISM
6.SQ.PRISM TO SQ.PRISM
( SKEW POSITION)
7.SQARE PRISM TO CONE ( from top )
8.CYLINDER TO CONE
COMMON SOLUTION STEPS
One solid will be standing on HP
Other will penetrate horizontally.
Draw three views of standing solid.
Name views as per the illustrations.
Beginning with side view draw three
Views of penetrating solids also.
On it’s S.V. mark number of points
And name those(either letters or nos.)
The points which are on standard
generators or edges of standing solid,
( in S.V.) can be marked on respective
generators in Fv and Tv. And other
points from SV should be brought to
Tv first and then projecting upward
To Fv.
Dark and dotted line’s decision should
be taken by observing side view from
it’s right side as shown by arrow.
Accordingly those should be joined
by curvature or straight lines.
Note:
Incase cone is penetrating solid Side view is not necessary.
Similarly in case of penetration from top it is not required.
93. X Y
1
2
3
4
a”
g” c”
e”
b”
f” d”
h”
4” 1”3” 2”
1’ 2’4’ 3’
a’
b ’h’
c’g’
d’f’
a’
CASE 1.
CYLINDER STANDING
&
CYLINDER PENETRATING
Problem: A cylinder 50mm dia.and 70mm axis is completely penetrated
by another of 40 mm dia.and 70 mm axis horizontally Both axes intersect
& bisect each other. Draw projections showing curves of intersections.
94. X Y
a”
d” b”
c”
4” 1”3” 2”
1’ 2’4’ 3’
1
2
3
4
a’
d’
b’
c’
a’
c’
d’
b’
CASE 2.
CYLINDER STANDING
&
SQ.PRISM PENETRATING
Problem: A cylinder 50mm dia.and 70mm axis is completely penetrated
by a square prism of 25 mm sides.and 70 mm axis, horizontally. Both axes
Intersect & bisect each other. All faces of prism are equally inclined to Hp.
Draw projections showing curves of intersections.
95. X Y
CASE 3.
CYLINDER STANDING
&
CONE PENETRATING
Problem: A cylinder of 80 mm diameter and 100 mm axis
is completely penetrated by a cone of 80 mm diameter and
120 mm long axis horizontally.Both axes intersect & bisect
each other. Draw projections showing curve of intersections.
1
2 8
3 7
4 6
5
7’
6’ 8’
1’ 5’
2’ 4’
3’
96. X Y
a”
d” b”
c”
a’
c’
a’
d’
b’
c’
d’
b’
1
2
3
4
1’ 2’4’ 3’ 4” 1”3” 2”
CASE 4.
SQ.PRISM STANDING
&
SQ.PRISM PENETRATING
Problem: A sq.prism 30 mm base sides.and 70mm axis is completely penetrated
by another square prism of 25 mm sides.and 70 mm axis, horizontally. Both axes
Intersects & bisect each other. All faces of prisms are equally inclined to Vp.
Draw projections showing curves of intersections.
97. X Y
1
2
3
4
4” 1”
3” 2”
1’ 2’4’ 3’
b
e
a
c
d
f
b
b
c
d
e e
a
a
f f
CASE 5. CYLINDER STANDING & TRIANGULAR PRISM PENETRATING
Problem: A cylinder 50mm dia.and 70mm axis is completely penetrated
by a triangular prism of 45 mm sides.and 70 mm axis, horizontally.
One flat face of prism is parallel to Vp and Contains axis of cylinder.
Draw projections showing curves of intersections.
98. X Y
1
2
3
4
1’ 2’4’ 3’ 4” 1”3” 2”
300
c”
f”
a’
f’
c’
d’
b’
e’
CASE 6.
SQ.PRISM STANDING
&
SQ.PRISM PENETRATING
(300 SKEW POSITION)
Problem: A sq.prism 30 mm base sides.and 70mm axis is
completely penetrated by another square prism of 25 mm side
s.and 70 mm axis, horizontally. Both axes Intersect & bisect
each other.Two faces of penetrating prism are 300 inclined to Hp.
Draw projections showing curves of intersections.
99. X Y
h
a
b
c
d
e
g
f
1
2
3
4
5
6
10
9
8
7
a’ b’h’ c’g’ d’f’ e’
5 mm OFF-SET
1’
2’
5’
4’
3’
6’
CASE 7.
CONE STANDING & SQ.PRISM PENETRATING
(BOTH AXES VERTICAL)
Problem: A cone70 mm base diameter and 90 mm axis
is completely penetrated by a square prism from top
with it’s axis // to cone’s axis and 5 mm away from it.
a vertical plane containing both axes is parallel to Vp.
Take all faces of sq.prism equally inclined to Vp.
Base Side of prism is 0 mm and axis is 100 mm long.
Draw projections showing curves of intersections.
100. CASE 8.
CONE STANDING
&
CYLINDER PENETRATING
h
a
b
c
d
e
g
f
a’ b’h’ c’g’ d’f’ e’ g” g”h” a”e” b”d” c”
1
2
3
4
5
6
7
8
X Y
o”
o’
1
1
3
3
5 5
6
7,
8,2
2
4 4
Problem: A vertical cone, base diameter 75 mm and axis 100 mm long,
is completely penetrated by a cylinder of 45 mm diameter. The axis of the
cylinder is parallel to Hp and Vp and intersects axis of the cone at a point
28 mm above the base. Draw projections showing curves of intersection.