Year 8 Angles Worksheet — Level 3 — Answers
Answer sheet with worked solutions for the Year 8 angles worksheet.
Success TutoringWorksheetsAnswer sheetYear 8 · Mathematics · AnglesYear 8 Angles Worksheet — Level 3 — Answers
State the angle rule you use.
1.An isosceles triangle has an apex angle of 72°. Find each base angle.
Answer: 54°
- Base angles are equal: (180 − 72) ÷ 2
- = 108 ÷ 2 = 54
2.Two angles on a straight line are 81° and x°. Find x.
Answer: x = 99
- Angles on a straight line add to 180°
- x = 180 − 81 = 99
3.An isosceles triangle has an apex angle of 30°. Find each base angle.
Answer: 75°
- Base angles are equal: (180 − 30) ÷ 2
- = 150 ÷ 2 = 75
4.An isosceles triangle has an apex angle of 59°. Find each base angle.
Answer: 60.5°
- Base angles are equal: (180 − 59) ÷ 2
- = 121 ÷ 2 = 60.5
5.An isosceles triangle has an apex angle of 63°. Find each base angle.
Answer: 58.5°
- Base angles are equal: (180 − 63) ÷ 2
- = 117 ÷ 2 = 58.5
6.An isosceles triangle has an apex angle of 34°. Find each base angle.
Answer: 73°
- Base angles are equal: (180 − 34) ÷ 2
- = 146 ÷ 2 = 73
7.Two angles of a triangle are 69° and 90°. Find the third angle.
Answer: 21°
- Angles in a triangle add to 180°
- 180 − 69 − 90 = 21
8.Two angles on a straight line are 29° and x°. Find x.
Answer: x = 151
- Angles on a straight line add to 180°
- x = 180 − 29 = 151
9.Two angles of a triangle are 103° and 48°. Find the third angle.
Answer: 29°
- Angles in a triangle add to 180°
- 180 − 103 − 48 = 29
10.An isosceles triangle has an apex angle of 73°. Find each base angle.
Answer: 53.5°
- Base angles are equal: (180 − 73) ÷ 2
- = 107 ÷ 2 = 53.5
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