Year 7 Angles in Polygons Worksheet — Level 2 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 7 angles worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Mathematics · AnglesYear 7 Angles in Polygons Worksheet — Level 2 — Practice Set 2 — 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 nonagon.
Answer: 1,260°
- Angle sum = (n − 2) × 180°
- (9 − 2) × 180° = 1,260°
2.Find the size of each interior angle of a regular pentagon.
Answer: 108°
- Angle sum = (5 − 2) × 180° = 540°
- 540° ÷ 5 = 108°
3.Find the size of each exterior angle of a regular 15-sided polygon.
Answer: 24°
- Exterior angles add to 360°
- 360° ÷ 15 = 24°
4.Each exterior angle of a regular polygon is 30°. How many sides does it have?
Answer: 12
- Exterior angles add to 360°
- 360 ÷ 30 = 12 sides
5.Find the sum of the interior angles of a dodecagon.
Answer: 1,800°
- Angle sum = (n − 2) × 180°
- (12 − 2) × 180° = 1,800°
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 pentagon.
Answer: 72°
- Exterior angles add to 360°
- 360° ÷ 5 = 72°
8.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
9.Find the sum of the interior angles of a 15-sided polygon.
Answer: 2,340°
- Angle sum = (n − 2) × 180°
- (15 − 2) × 180° = 2,340°
10.Find the size of each interior angle of a regular 20-sided polygon.
Answer: 162°
- Angle sum = (20 − 2) × 180° = 3,240°
- 3,240° ÷ 20 = 162°
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