8th Grade Angles in Polygons Worksheet — Level 1 — Practice Set 2 — Answers
Answer sheet with worked solutions for the 8th Grade angles worksheet.
Success TutoringWorksheetsAnswer sheet8th Grade · Mathematics · Angles8th Grade Angles in Polygons Worksheet — Level 1 — 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 hexagon.
Answer: 720°
- Angle sum = (n − 2) × 180°
- (6 − 2) × 180° = 720°
2.Find the size of each interior angle of a regular decagon.
Answer: 144°
- Angle sum = (10 − 2) × 180° = 1,440°
- 1,440° ÷ 10 = 144°
3.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°
4.Find the size of each interior angle of a regular dodecagon.
Answer: 150°
- Angle sum = (12 − 2) × 180° = 1,800°
- 1,800° ÷ 12 = 150°
5.Find the sum of the interior angles of a nonagon.
Answer: 1,260°
- Angle sum = (n − 2) × 180°
- (9 − 2) × 180° = 1,260°
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 an octagon.
Answer: 1,080°
- Angle sum = (n − 2) × 180°
- (8 − 2) × 180° = 1,080°
8.Find the size of each interior angle of a regular triangle.
Answer: 60°
- Angle sum = (3 − 2) × 180° = 180°
- 180° ÷ 3 = 60°
9.Find the sum of the interior angles of a 14-sided polygon.
Answer: 2,160°
- Angle sum = (n − 2) × 180°
- (14 − 2) × 180° = 2,160°
10.Find the size of each interior angle of a regular pentagon.
Answer: 108°
- Angle sum = (5 − 2) × 180° = 540°
- 540° ÷ 5 = 108°
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