2025 · Q27
The length of an arc of a circle of radius 4 cm is π cm. What is the magnitude of the angle subtended by the arc at the centre?
Elementary MathematicsTrigonometry
- Aπ
- Bπ/2
- Cπ/3
- Dπ/4
Explanation
Arc length s, radius r and central angle theta (in radians) satisfy s = r*theta. Here theta = s/r = pi/4, so the arc subtends pi/4 radians at the centre. Hence option (d).