Theorem of Pythagoras.

This set of material represents three cases of the theorem of Pythagoras.
The First: Two sides of the triangle are equal.

The Second:  The sides of the triangle are in the proportion of 3: 4: 5. The builders right angle triangle.

The Third : The general case (the Euclidean demonstration).

The material consists of three green metal plates with bottoms and inset pieces.