Question 23
Mensuration of Plane ShapesAn arc of a circle subtends an angle of 30° on the circumference of a circle of radius 21cm. Find the length of the arc. [π = 22/7]
- A.11cm
- B.22cm
- C.44cm
- D.66cm
Show the answer and explanation
Answer: B (22cm)
Explanation
The angle at the centre is twice the angle at the circumference, so it is 60°. Arc length = 60/360 × 2 × 22/7 × 21 = 22cm.