passwella.
Menu

UI Post-UTME Mathematics 2021 (Model questions) Question 10

Question 10

Mensuration of Plane Shapes

An arc of the length 16πcm subtends an angle of 80° at the centre of the circle. Find the radius of the circle

  1. A.32cm
  2. B.36cm
  3. C.28cm
  4. D.24cm
Show the answer and explanation

Answer: B (36cm)

Explanation

(80/360) × 2πr = 16π gives (4/9)r = 16, so r = 36 cm.