What is the surface area (in cm2 ) of a sphere whose diameter is 21 cm?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 1386
Given that
Diameter = 21cm
Radius = diameter/2 = 21/2 = 10.5cm
Therefore surface area of sphere = 4π/r2
= 4 × 22/7 × 10.5 × 10.5
= 1386 cm2
Hence the surface area of the sphere is 1386cm2