`SA = (2)(3.14)(r^2) + (2)(3.14)rh`

`SA = 6.28r^2 + 6.28rh` Subtract `6.28r^2`

`SA - 6.28r^2 = 6.28rh` Divide both sides by `6.28r`

`(SA-6.28r^2)/(6.28r) = (6.28rh)/(6.28r)`

`h = (SA-6.28r^2)/(6.28r)`

or

`h = (SA)/(6.28r) - r`

`SA = (2)(3.14)(r^2) + (2)(3.14)rh`

`SA = 6.28r^2 + 6.28rh` Subtract `6.28r^2`

`SA - 6.28r^2 = 6.28rh` Divide both sides by `6.28r`

`(SA-6.28r^2)/(6.28r) = (6.28rh)/(6.28r)`

`h = (SA-6.28r^2)/(6.28r)`

or

`h = (SA)/(6.28r) - r`