Question

if the surface area of sphere is 154cm then it's radius in cms

Answer 1

Let radius of Sphere be r.

Surface area of sphere= 154 cm2

4nr2 =154 

r2 =154*7/4*22  =7*7/2*2

r =7/2 =3.5cm

Answer 2

Let the radius of sphere be r

surface are of sphere=4×pie×r^2

154=4×22/7×r^2

r^2=154×7/22×4

r^2=49/4

r=7/2

r=3.5cm