1. Geometry{Shapes, Lines and Angles}

2. Introduction Geometry is all about… Shapes Lines Angles

3. Angles Question: What is an “angle”? Answer: An angle is the amount of rotation needed to turn from one direction to look in a different direction

4. Angles Question: How do we measure the size of an angle? Answer: Using a protractor

5. Types of Angles Question: What are the different types of angles? Answer: There are 5 types of angles… Acute angles, a right angle, reflex angles, a straight angle and obtuse angles

7. Types of Angles

8. Types of Angles Reflex Angle Right Angle Acute Angle Straight Angle Obtuse Angle Full Rotation

9. Complimentary and Supplementary Angles Question: What are complimentary and supplementary angles? Answer: Complimentary angles are angles that add to 90o Supplementary angles are angles that add to 180o

10. Types of Angles Complimentary Angles Supplementary Angles a = 90 − b a = 180 − b b = 90 − a b = 180 − a

11. Let’s see how we are going so far… So that you can check if you understand the information that you have just been explained to you, have a go at the following questions from your textbook… Exercise 5A – Questions 2, 3 (a to e) and 4 * Please remember to check your answer when you finish each question and get help from your teacher as soon as you can not work out how to do a question!

12. The Angles Inside Shapes If we draw a triangle, measure the size of the angles in each of the corners and add the angles together we find that the answer is… 180o This answer is the same for all triangles! The same thing happens for all shapes that have straight sides; such as squares, pentagons, octagons etc.

13. The Angles Inside Shapes

14. Measuring Shapes and Objects We live in a three-dimensional world! Every object you can see has three dimensions that can be measured... Length Width Height The room we are sitting in can be described by these three dimensions, as can the person sitting next to you!

17. length and height

18. width and height A 3– dimensional object (i.e. a 3D object)has a length, a width and a height.

20. An edge is a line where two faces join together

23. Time for an activity… Ask your teacher for the worksheet called… Faces, Edges and Vertices This worksheet is one of the homework sheets that you must hand in as part of your Learning Assessment!!!