Question

Can some one help me with this

Answer 1

All this is saying is:      "Solve this equation for 'r':   V =  π r² h ."
You should be able to do that.

                                              V          =  π r² h

Divide each side by 'π':       V / π    =      r² h

Divide each side by 'h':       V / π h  =     r²

Square root each side:        r = √ ( V / π h)  .