A chord AB of a circle has a length of 10 cm. The angle subtended by the chord at a point C on the major arc is 30°. Find the radius of the circle.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 10 cm.
Chord AB = 10 cm, and angle subtended at the major arc at C = 30°
Angle at center = 2 × 30° = 60°
Chord length formula: Chord = 2R sin(θ/2)
⇒ 10 = 2R sin(60°/2) = 2R sin 30°
⇒ 10 = 2R × (1/2)
⇒ R = 10 cm