2019 · Q54
A piece of wire of length 33 cm is bent into an arc of a circle of radius 14 cm. What is the angle subtended by the arc at the centre of the circle?
Elementary MathematicsCircles
- A75°
- B90°
- C135°
- D150°
Explanation
Arc length l = rθ gives θ = l/r = 33/14 radians. Converting: (33/14) × (180/π)° ≈ 2.357 × 57.3° ≈ 135.06°, i.e. 135°. The answer is (C).