Here's the deal; there was this Greek guy named Pythagoras, who lived over
2,000 years ago during the sixth century B.C.E. Pythagoras spent a lot of time
thinking about math, astronomy, and music. One idea he came up with was a mathematical equation that's
used all the time, for example in architecture, construction, and
measurement.

His equation is simple: a^{2 }+ b^{2} = c^{2}.

What it means is that in a right triangle (where one angle equals 90°),
the sum of the squares of two sides equals the square of the hypotenuse (the
longest side).

Or, to put it another way:

Check it out—you can show that the Pythagorean theorem works.