Geometry and TrigonometryMediumArea of a sector in terms of π
Geometry and Trigonometry practice question
A circle has a radius of 6 centimetres. What is the area, in square centimetres, of a sector with a central angle of 120°?
- A. 12πCorrect
- B. 36π
- C. 4π
- D. 18π
Answer: A. 12π
120° is a third of the circle; the full area is 36π, so the sector is 12π.
Why the other answers are wrong
- B. 36π
- 36π is the whole circle.
- C. 4π
- 4π uses a third of the radius squared incorrectly (6²/3 = 12, not 4).
- D. 18π
- 18π is a half circle.
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