Hello, I would be grateful for any help with regard to formulas for the following:

"A piece of string is cut into two pieces of different lengths. These are then used to form two different shapes with equal areas. Find the measurements of the shapes that satisfy the conditions shown as follows.

Thanks in advance,

- String: 90cm; Shapes: square and rectangle
- String: 44cm; Shapes: rectangle and a right triangle
- String: 52cm; Shapes: parallelogram and square"

Kim