I need to calculate the diameter of a cylinder . However the cylinder has a hemisphere as a lid and a flat bottom.

I am given the overall surface area which is 2M square

The overall height is 84cm. Thats it

I can formulate the cylinder diameter if it didn't have a hemisphere top using quadratics however i just cant see how to get this.

SA of hemisphere = 2 pi r square

Sa of base = 1 Pi r square

Cylinder height H= h - r

Cylinder area = 2 pi r H

any help please.....