Year 9 Angles Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 angles worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · AnglesYear 9 Angles Worksheet — Level 2 — Practice Set 4 — Answers
State the angle rule you use.
1.Two angles of a triangle are 79° and 83°. Find the third angle.
Answer: 18°
- Angles in a triangle add to 180°
- 180 − 79 − 83 = 18
2.Two angles on a straight line are 100° and x°. Find x.
Answer: x = 80
- Angles on a straight line add to 180°
- x = 180 − 100 = 80
3.Two angles on a straight line are 141° and x°. Find x.
Answer: x = 39
- Angles on a straight line add to 180°
- x = 180 − 141 = 39
4.Two angles of a triangle are 28° and 47°. Find the third angle.
Answer: 105°
- Angles in a triangle add to 180°
- 180 − 28 − 47 = 105
5.Two angles on a straight line are 138° and x°. Find x.
Answer: x = 42
- Angles on a straight line add to 180°
- x = 180 − 138 = 42
6.Two angles on a straight line are 154° and x°. Find x.
Answer: x = 26
- Angles on a straight line add to 180°
- x = 180 − 154 = 26
7.Two angles of a triangle are 67° and 106°. Find the third angle.
Answer: 7°
- Angles in a triangle add to 180°
- 180 − 67 − 106 = 7
8.Two angles of a triangle are 44° and 98°. Find the third angle.
Answer: 38°
- Angles in a triangle add to 180°
- 180 − 44 − 98 = 38
9.Two angles of a triangle are 79° and 26°. Find the third angle.
Answer: 75°
- Angles in a triangle add to 180°
- 180 − 79 − 26 = 75
10.Two angles of a triangle are 38° and 112°. Find the third angle.
Answer: 30°
- Angles in a triangle add to 180°
- 180 − 38 − 112 = 30
Marking tips
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