Year 7 Angles in Polygons Worksheet — Level 1 — Answers
Answer sheet with worked solutions for the Year 7 angles worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Mathematics · AnglesYear 7 Angles in Polygons Worksheet — Level 1 — 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 20-sided polygon.
Answer: 3,240°
- Angle sum = (n − 2) × 180°
- (20 − 2) × 180° = 3,240°
2.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°
3.Find the sum of the interior angles of a hexagon.
Answer: 720°
- Angle sum = (n − 2) × 180°
- (6 − 2) × 180° = 720°
4.Find the size of each interior angle of a regular nonagon.
Answer: 140°
- Angle sum = (9 − 2) × 180° = 1,260°
- 1,260° ÷ 9 = 140°
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 20-sided polygon.
Answer: 162°
- Angle sum = (20 − 2) × 180° = 3,240°
- 3,240° ÷ 20 = 162°
7.Find the sum of the interior angles of a nonagon.
Answer: 1,260°
- Angle sum = (n − 2) × 180°
- (9 − 2) × 180° = 1,260°
8.Find the size of each interior angle of a regular quadrilateral.
Answer: 90°
- Angle sum = (4 − 2) × 180° = 360°
- 360° ÷ 4 = 90°
9.Find the sum of the interior angles of a quadrilateral.
Answer: 360°
- Angle sum = (n − 2) × 180°
- (4 − 2) × 180° = 360°
10.Find the size of each interior angle of a regular triangle.
Answer: 60°
- Angle sum = (3 − 2) × 180° = 180°
- 180° ÷ 3 = 60°
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