Question

the height of a right circular cylinder is 21cm.lis curved surface area is 924sq cm.then its volume is .

Answer 1

CSA of cylinder = 2*22/7*r*h
                 924   = 2*22/7*r*21
                    r     = 924*7 / 2*22*21
                    r     = 6468 / 924
                    r     = 7 cm

vol. of cylinder    = 22/7*r^2*h
                           = 22/7*7*7*21
                           =  3234 cm^3 

Answer 2

Csa of cylinder =2pie*r*h
924=2*22/7*r*21
924=132*r
924/132=r
7cm=r

Volume of cylinder =pie r^2 h
=22/7*7*7*21
=147*22
=3234cm^3 is the answer

Hope it is helpful