Year 7 Angles in Polygons Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 7 angles worksheet.
Year 7 Angles in Polygons Worksheet — Level 2 — Practice Set 4 — Answers
Interior angle sum = (n − 2) × 180°. The exterior angles of any convex polygon add to 360°.
1.Find the sum of the interior angles of a dodecagon.
Answer: 1,800°
- Angle sum = (n − 2) × 180°
- (12 − 2) × 180° = 1,800°
2.Find the size of each interior angle of a regular 30-sided polygon.
Answer: 168°
- Angle sum = (30 − 2) × 180° = 5,040°
- 5,040° ÷ 30 = 168°
3.Find the size of each exterior angle of a regular quadrilateral.
Answer: 90°
- Exterior angles add to 360°
- 360° ÷ 4 = 90°
4.Each exterior angle of a regular polygon is 15°. How many sides does it have?
Answer: 24
- Exterior angles add to 360°
- 360 ÷ 15 = 24 sides
5.Find the sum of the interior angles of a 11-sided polygon.
Answer: 1,620°
- Angle sum = (n − 2) × 180°
- (11 − 2) × 180° = 1,620°
6.Find the size of each interior angle of a regular quadrilateral.
Answer: 90°
- Angle sum = (4 − 2) × 180° = 360°
- 360° ÷ 4 = 90°
7.Find the size of each exterior angle of a regular 36-sided polygon.
Answer: 10°
- Exterior angles add to 360°
- 360° ÷ 36 = 10°
8.Each exterior angle of a regular polygon is 45°. How many sides does it have?
Answer: 8
- Exterior angles add to 360°
- 360 ÷ 45 = 8 sides
9.Find the sum of the interior angles of a 20-sided polygon.
Answer: 3,240°
- Angle sum = (n − 2) × 180°
- (20 − 2) × 180° = 3,240°
10.Find the size of each interior angle of a regular 15-sided polygon.
Answer: 156°
- Angle sum = (15 − 2) × 180° = 2,340°
- 2,340° ÷ 15 = 156°
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