How do you use the Pythagorean theorem to find the length of a side in a right triangle?

To find a side length using the Pythagorean theorem, identify the lengths of two sides. For legs ‘a’ and ‘b’, and hypotenuse ‘c’, the formula is a² + b² = c². Rearrange to solve for the unknown side: a² = c² – b² or b² = c² – a², then take the square root.