Mon 1st OCt (Lesson 1) - Drawing and measuring angles greater than 180 degrees (reflex angles)

LEARNING OBJECTIVE: Discover how you can use a protractor to measure and draw angles greater than 180 degrees
SUCCESS CRITERIA: You will be able to draw and measure reflex angles.

ENGAGEGMENT ACTIVITY: Write down the answer to these sums (WITHOUT A CALCULATOR)

1. 200 - 180
2. 280 - 180
3. 260 - 180
4. 320 - 180
5. 315 - 180
6. 192 - 180
7. 232 - 180
8. 311 - 180
9. 293 - 180
10. 269 - 180

LESSON: Use IWB to show how to measure reflex angles using a protractor.

Measure these angles as accurately as possible  - remember you must be within 1 degree of my measurement to be correct.

Once you have got all those measured accurately I would like you to draw these angles accurately

1. 200°
2. 280°
3. 260°
4. 320°
5. 315°
6. 192°
7. 232°
8. 311°
9. 293°
10. 269°

PLENARY: Students check their answers on my computer to angles measured. They measure and peer mark their accurate drawings.

EXTENSION: The interior angles of some regualr polygons are losted below. Can you use your protractor to draw them accurately. They will all have sides of length 5cm

Equilateral Triangle - 60°

Regular Pentagon - 108°

Regular Hexagon - 120°

Regular OCtagon - 145°

Regular nonagon - 160°

Regular Decagon - 144°