If the curved surface area of a hemisphere is 154 cm2 find its diameter.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 9.9 cm.
Curved surface area of hemisphere = 2πr2 = 154
⇒ 2 × (22/7) × r2 = 154
⇒ r2 = 154 × 7/44 = 49/2
⇒ r = 14/√2
Diameter = 2r = 2 × (14/√2) = 7√2 ≈ 9.9 cm