A cylindrical kite frame is to be constructed from a 4-m length of light bendable rod.

The frame will be made up of 2 circles joined by four straight rods of equal length. In order to maximize lift, the kite frame must be constructed to maximize the volume of the cylinder.

In what lengths should the peices be cut to optimize the kites flight?

I know the answer but every time I try to do it, I get a different one, help would be appreicated greatly.