1. Geometry Types of angles How to draw an angle Angles around points
Angles on straight lines
Triangles
Angles made using parallel lines

2. Measuring, classifying and drawing angles (3 letter names)H H B B ∠ ∠

3. Measuring, classifying and drawing anglesH H K B B J ∠ ∠

4. Classifying angles
A revolution (or perigon) measures 360° and is shown by the symbol .
An acute angle measures less than 90°.
A right angle measures 90° and is shown by the symbol .

5. Classifying angles An obtuse angle measures between 90° and 180°.
A straight angle measures 180°.
A reflex angle measures between 180° and 360°.

6. Name the angles and classify each angle
Acute ∠ABC
Reflex ∠CGH
Acute ∠OMN
Obtuse ∠NML

7. Drawing angles Draw an angle of 65°
Start at o (use inside scale for this one)

8. Drawing angles Draw an angle of 145°
Start at o (use inside scale for this one)

9. Drawing angles
Draw an angle of 245°
245° ° = 65 °

10. Angle rules 1. Angles around a point sum to 360°.
2. Angles on a straight line sum to 180°.

11. Angle rules 3. Angles in a triangle sum to 180°. ? = 180° – 80° – 40°
? = 60°

12. Angle rules 4. Corresponding angles are equal.
(Made with parallel lines)
4. Corresponding angles are equal.

13. Angle rules
(Made with parallel lines)
5. Alternate angles are equal.

14. Angle rules
(Made with parallel lines)
6. Allied angles sum to 180°.

15. Types of Triangle 2. Equilateral 1. Isoceles 4. Scalene
2 sides & 2 angles the same
3 sides & 3 angles the same
4. Scalene
3. Right angled
No sides & no angles the same
(but could be right angled!)
(Could also be isoceles!)