8th Grade Angles Worksheet — Level 3 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 8th Grade angles worksheet.
Success TutoringWorksheetsAnswer sheet8th Grade · Mathematics · Angles8th Grade Angles Worksheet — Level 3 — Practice Set 3 — Answers
State the angle rule you use.
1.Three angles meet at a point: 121°, 51° and x°. Find x.
Answer: x = 188
- Angles at a point add to 360°
- x = 360 − 121 − 51 = 188
2.Two angles on a straight line are 95° and x°. Find x.
Answer: x = 85
- Angles on a straight line add to 180°
- x = 180 − 95 = 85
3.An isosceles triangle has an apex angle of 23°. Find each base angle.
Answer: 78.5°
- Base angles are equal: (180 − 23) ÷ 2
- = 157 ÷ 2 = 78.5
4.Two angles of a triangle are 105° and 64°. Find the third angle.
Answer: 11°
- Angles in a triangle add to 180°
- 180 − 105 − 64 = 11
5.Two angles on a straight line are 21° and x°. Find x.
Answer: x = 159
- Angles on a straight line add to 180°
- x = 180 − 21 = 159
6.Two angles of a triangle are 115° and 31°. Find the third angle.
Answer: 34°
- Angles in a triangle add to 180°
- 180 − 115 − 31 = 34
7.Three angles meet at a point: 54°, 149° and x°. Find x.
Answer: x = 157
- Angles at a point add to 360°
- x = 360 − 54 − 149 = 157
8.An isosceles triangle has an apex angle of 74°. Find each base angle.
Answer: 53°
- Base angles are equal: (180 − 74) ÷ 2
- = 106 ÷ 2 = 53
9.Two angles of a triangle are 45° and 119°. Find the third angle.
Answer: 16°
- Angles in a triangle add to 180°
- 180 − 45 − 119 = 16
10.An isosceles triangle has an apex angle of 57°. Find each base angle.
Answer: 61.5°
- Base angles are equal: (180 − 57) ÷ 2
- = 123 ÷ 2 = 61.5
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