Question 31
Mensuration of SolidsA cone with the sector angle of 45° is cut out of a circle of radius r cm. Find the base radius of the cone.
- A.r/16cm
- B.r/8cm
- C.r/4cm
- D.r/2cm
Show the answer and explanation
Answer: B (r/8cm)
Explanation
The arc of the sector becomes the base circumference: (45/360) × 2πr = 2πR, so R = r/8.