Multiple choice

An arc of a circle of radius 42 cm. subtends an angle of 720 at its centre. Find the length of the arc.

  1. 38.6 cm.

  2. 48.4 cm.

  3. 49.5 cm.

  4. 52.8 cm.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Arc length formula: l = (θ/360) × 2πr. Given θ = 72°, r = 42 cm. l = (72/360) × 2 × (22/7) × 42 = (1/5) × 2 × 22 × 6 = 52.8 cm. Option D is correct.