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Geometric Proof of Pythagorean Theorem

The Pythagorean theorm is the geometric result for a right (90 degree) triangle that

`("hypotenuse")^2=("base")^2+("altitude")^2`

This theorem is probably the most important in all of geometry. It was probably of great importance in building the pyramids.

Alternately we can write:

`c^2=b^2+a^2`

where base and altitude refer to the two perpendicular sides of a right triangle (one with a 90 degree angle)
and hypotenuse, c, is the diagonal connecting the free end of the base, b, to the free end of the altitude, a, as shown in the small diagram here. It's important to note that partiularcombinations like a=4, b=3 result in exactly c=5. The ancients used integer (counting) arithmetic so I think that combination was used a lot in their constructions.

It should be noted that in 3 or more dimensions the Pythagorean theorem takes the form

`l^2=deltax^2+deltay^2+deltaz^2+deltau^2+....`

where `l` is the distance between the starts and ends of connected segments `deltax` etc in the (`x,y,z,w,...`) coordinate system.

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