Question 27
Mensuration of SolidsA cone is formed by bending a sector of a circle having an angle of 210°. Find the radius of the base of the cone if the diameter of the circle is 12cm.
- A.7.00cm
- B.1.75cm
- C.√21cm
- D.3.50cm
- E.2√21cm
Show the answer and explanation
Answer: D (3.50cm)
Explanation
The arc becomes the base circumference: 2πr = 210/360 × 2π × 6, so r = 210/360 × 6 = 3.5cm.