Step 1 : Introduction to the question "The Pythagorean theorem helps calculate the size of which shape?"
...In mathematics, the Pythagorean theorem is a fundamental relation in Euclidean geometry among the three sides of a right triangle. The theorem can be written in one short equation: a² + b² = c². The theorem states that the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides. The theorem, named after the ancient Greek mathematician Pythagoras, is used any time we have a right triangle, we know the length of two sides, and we want to find the third side.
