If the angle subtended by a chord AC at the center O is 120° and the length of the chord AC is 10√3 cm, what is the radius of the circle?
Show answer & explanation
Correct answer: C
Explanation
Given:
∠AOC = 120°
Chord AC = 10√3 cm
Formula:
Chord = 2R sin(θ/2)
10√3 = 2R sin(120°/2)
10√3 = 2R sin60°
10√3 = 2R × √3/2
10√3 = R√3
R = 10
Radius of the circle = 10 cm.