Multiple choice

An arc of a circle of radius 42 cm subtends an angle of (72^o) 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

Use arc length formula l = (θ/360) × 2πr. Substituting θ=72° and r=42 cm gives l = (72/360) × 2π × 42 = (1/5) × 264 = 52.8 cm. The key is recognizing 72° is 1/5 of 360°, so the arc is 1/5 of the circumference.

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