Polygons Mixed Exercise Pg 132 133 Exercise 6

Polygons Mixed Exercise Pg 132 – 133 Exercise 6 h No. 1 to No. 6

1. Find the size of each marked Angle Sum of exterior angles = 360° 110°+ 130°= 240° m = 360°- 240°= 120° 2 p = 180°- 120°= 60° 1

2. Find the size of each exterior angle of a regular polygon with 12 sides. What is the size of each interior angle? Sum of exterior angles = 360°÷ 12 = 30° 1 Interior + Exterior = 180° One interior angle = 180°- 30°= 150° 1

3. Find the size of the angle marked x° Sum of interior angles = (5 -2) x 180° Sum of interior angles = 3 x 180°= 540° 90°+ 130° + 120° + 80° = 420° x = 540°- 420°= 120° Pentagon 5 sides 2 1

4. How many sides has a regular polygon if each interior angle is 168°? Interior + Exterior = 180° One exterior angle = 180° - 168°= 12° 1 12°x n = 360°? ? n = 360° ÷ 12° = 30 SIDES! 2

5. Is it possible for each exterior angle in a regular polygon to be a) 45° b)75° a) 45° x n = 360°? ? ? n = 360° ÷ 45°= 8 SIDES (OCTAGON) 2 b) 75° x n = 360°? ? ? n = 360° ÷ 75°= 4. 8 (not possible!) 2

6. Find the size of the marked angle Sum of interior angles = (4 -2) x 180° Sum of interior angles = 2 x 180°= 360° 1 120° + 80° = 280° 360°- 280°= 80° Quadrilateral 4 sides X = 180° – 80° = 100° 1 Mark for your presentation of working: Is it good? (1), Is it okay but could be better (0. 5), Do you think you could have done much better? (0) 2 1

Polygons Plenary Quiz