Theorem of Pythagoras

This set represents 3 cases of the Theorem of Pythagoras.  In the first, 2 sides of the triangle are equal; in the second, the sides of the triangle are in the proportion of 3: 4: 5; & in the third, the general case (the Euclidean demonstration) is shown.  The material consists of 3 green metal plates with blue, red, yellow & white inset pieces.