Question 27
Mensuration of Plane ShapesCalculate the length in cm of the arc of a circle of diameter 8cm which subtends an angle of 22° at the centre of the circle.
- A.2π
- B.π
- C.⅔π
- D.π/2
Show the answer and explanation
Answer: D (π/2)
Explanation
Arc length = (θ/360) × 2πr with r = 4cm. With 22½° this is (22.5/360) × 8π = π/2 cm; with 22° it is about 0.49π, which is still nearest to π/2.