Class 6 Measuring Angles — practice questions with answers
Geometry · 5 sample questions from the school syllabus. Try each one, then open the answer and the worked solution.
1. In which unit do we usually measure the size of an angle?
- AMillimetres
- BCentimetres
- CDegrees
- DSquare centimetres
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Answer: C) Degrees
Angles are measured in degrees (°). A complete turn is 360°. Centimetres measure length, and square centimetres measure area.
2. Arm OA lies on the LEFT side along the base line. What is ∠AOB?
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Answer: A) 130°
OA is on the left, where the INNER scale starts at 0. Reading the inner scale at OB gives 130°. The angle is clearly obtuse, which confirms it.
3. Meena put arm OA on the 20 mark instead of 0, and OB crossed at 85 on the same scale. She wrote ∠AOB = 85°. What is the correct measure?
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Answer: A) 65°
When OA is not on 0, subtract the two readings: 85 − 20 = 65°. (105° adds them.)
4. Three equal angles fit together around a point with no gaps. What is the size of each?
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Answer: C) 120°
Angles around a point add to 360°. 360° ÷ 3 = 120°. (60° divides 180° instead.)
5. On a protractor, arm OA crosses the OUTER scale at 35 and arm OB crosses the INNER scale at 35. What is ∠AOB?
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Answer: A) 110°
The inner 35 is at the same place as the outer 145 (because 180 − 35 = 145). On the outer scale the arms are at 35 and 145, so ∠AOB = 145 − 35 = 110°.