The curved surface area of a cylinder is 7920 cm2. If its base radius is 21 cm, then its height will be __________ (use π = ).
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 60 cm.
Curved Surface Area = 2πrh
Given CSA = 7920, r = 21
⇒ 7920 = 2 × (22/7) × 21 × h
⇒ 7920 = 2 × 22 × 3 × h
⇒ 7920 = 132h
h = 7920 / 132
h = 60