1. QUADILATRERA
LS

2. What are quadilaterals?
A quadrilateral is a polygon with
four sides (or 'edges') and four
vertices or corners.

3. WHAT ARE
POLYGONS?
In geometry a polygon is traditionally a
plane figure that is bounded by a closed
path or circuit, composed of a finite
sequence of straight line segments (i.e., by
a closed polygonal chain ). These segments
are called its edges or sides, and the
points where two edges meet are the
polygon's vertices (singular: vertex) or
corners.

4. HOW IS A
QUADRILATERAL A
POLYGON?
A quadrilateral is a polygon. In fact
it is a 4-sided polygon, just like a
triangle is a 3-sided polygon, a
pentagon is a 5-sided polygon, and so
on.

5. QUAD means four
And
LATERAL means sides

6. A line segment drawn from one vertex of a
quadrilateral to the opposite vertex is
called a diagonal of the quadrilateral. AC
is a diagonal of quadrilateral ABCD, as is
BD.

7. TYPES OF
QUADILATERALS
There are seven types of quadrilaterals
that can be divided into two groups:
parallelograms and other quadrilaterals.
Rectangle Trapezium
Rhombus
Square Parallelogram

8. • PARALLELOGRAMQuadrilaterals
are
called
parallelograms if both pairs of
opposite sides are equal and parallel
to each other.
• OTHER QUADRILATERALSOther quadrilaterals include
trapeziums, kites and irregular
quadrilaterals

9. IRREGULAR
QUADILATERALS
An irregular quadrilateral does not
have any special properties.

10. COMPLEX
QUADILATERALS
When two sides cross over, you call it
a "Complex" or "Self-Intersecting"
quadrilateral like these:
They still have 4 sides, but two sides cross over.

11. ANGLE SUM OF A
QUADILATRAL
Draw a quadrilateral ABCD. Then
draw the diagonal AC to form two
triangles.

12. FINDING THE FOURTH
ANGLE OF A
QUADRILATERAL
If the measurements of three angles
of a quadrilateral are known, then
the missing angle can be calculated

13. ExampleFind the value of the pronumeral x in the
accompanying diagram. Give reasons for
your answer.

14. Solution:

15. OTHER NAMES
A quadrilateral can sometimes be
called:
• A Quadrangle ("four angles"), so it
sounds like "triangle"
• A Tetragon ("four and polygon"), so
it sounds like "pentagon", "hexagon",
etc.

16. END
OF
THE
PRESENTATION