Question

find the height of solid circular cylinder of total surface area 660cm and radius 5

Answer 1

Surface area means 2(pi)Rh
so that 2(pi)Rh=660.
put R=5, pi=3.14 or 22/7. solve the equation, You will get 'h' which you want.

Answer 2

Given the radius of the circular cylinder = 5cm.

Then the diameter of the circular cylinder d = 2r 

                                                                          = 2 * 5

                                                                          = 10cm.


Given that total surface area of the cylinder = 660cm

        2pir(r + h) = 660

        2 * 22/7 * 5 * (5 + h) = 660

       h + 5 = 660 * 1/2 * 7/22 * 1/5

      h + 5 = 21

      h = 16.


Therefore the height of the solid circular cylinder = 16 sq.cm.


Hope this helps!