Diagrammatic Proof of Pythagoras Theorem
Independence of Triangle Dimensions

First phase: righthand copy of lefthand picture
has the triangles rotated and then slid into position.
Triangles with the same color in the left and right diagrams
are counterparts in the
sense of Barwise and
Etchemendy. The blue areas in both diagrams therefore have the
same measure.

Second phase: shows the continuity of the correspondence;
as left triangle dimensions change, the identical change
appears on the right. Hence, the proof is independent of
relative side dimensions of the triangles.
I am afraid this Java applet is not one of the most elegant that
I have written. One day I will find the time to go back and clean
it up, providing you with slider bars to control (and pause!) the
animation as you please.
Click here to Redo the Animation
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