Question 50
Mensuration of SolidsAn open cone with base radius 28 cm and perpendicular height 96 cm was stretched to form a sector of a circle. Calculate the area of the sector. [Take π = 22/7]
- A.8800 cm2
- B.8448 cm2
- C.4400 cm2
- D.4224 cm2
Show the answer and explanation
Answer: A (8800 cm2)
Explanation
Slant height = √(282 + 962) = 100 cm. The sector is the cone's curved surface: πrl = 22/7 × 28 × 100 = 8800 cm2.