Gemetric Puzzle Challenge

[Guest]

Please try to solve this Geometric Puzzle Challenge.

You must design two geometric shapes.
With these two shapes you must construct both a circle or a square.
You must use both shapes in the construction of the circle or the square.
All of the two shapes used must be congruent.

Good luck. There is a solution.

[leesajohnson]

I'm not understanding the puzzle that which shape is to be used both or I can use single shape.

[ten2match]

Could the answer be a cross between half a rectangular and half a circle, when the two peaces connect you get a circle inside a rectangular or an ellipse inside a square.