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 15-sided polygon.
Answer: 2,340°
- Angle sum = (n − 2) × 180°
- (15 − 2) × 180° = 2,340°
2.Find the size of each interior angle of a regular 18-sided polygon.
Answer: 160°
- Angle sum = (18 − 2) × 180° = 2,880°
- 2,880° ÷ 18 = 160°
3.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°
4.Find the size of each interior angle of a regular octagon.
Answer: 135°
- Angle sum = (8 − 2) × 180° = 1,080°
- 1,080° ÷ 8 = 135°
5.Find the sum of the interior angles of a hexagon.
Answer: 720°
- Angle sum = (n − 2) × 180°
- (6 − 2) × 180° = 720°
6.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°
7.Find the sum of the interior angles of a dodecagon.
Answer: 1,800°
- Angle sum = (n − 2) × 180°
- (12 − 2) × 180° = 1,800°
8.Find the size of each interior angle of a regular dodecagon.
Answer: 150°
- Angle sum = (12 − 2) × 180° = 1,800°
- 1,800° ÷ 12 = 150°
9.Find the sum of the interior angles of a heptagon.
Answer: 900°
- Angle sum = (n − 2) × 180°
- (7 − 2) × 180° = 900°
10.Find the size of each interior angle of a regular nonagon.
Answer: 140°
- Angle sum = (9 − 2) × 180° = 1,260°
- 1,260° ÷ 9 = 140°
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