Question

Find the diameter of the sphere whose surface area is 154cm sq

Answer 1

Given,
Surface area= 154 cm²
Now,
4πr²= 154
2πr²= 77
44/7*r²= 77
(77*7)/44= r²
49/4= r²
r= 7/2
So,
Diameter= 2r= 7/2*2= 7 cm

Hope this helps you!

Answer 2

S.A. Of a sphere = 4×22/7×r^2 = 154 cm^2
=r^2 = 154×7/4×22
=r^2= 12.25
=r= √12.25
=r= 3.5 cm
Diameter = 2r
D= 2× 3.5
D= 7 cm