Use the Pythagorean Theorem to find the missing side length. someone please tell me what the Pythagorean Theorem is?

http://www.mathsisfun.com/pythagoras.html

The Pythagorean theorem is A2 + B2 = C2

The Pythagorean Theorem is a mathematical formula that relates to right triangles. It states that in a right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides.

In equation form, it can be written as:

c^2 = a^2 + b^2

Where c represents the length of the hypotenuse, and a and b represent the lengths of the other two sides.

To find the missing side length using the Pythagorean Theorem, you need to know the lengths of the other two sides. Simply substitute the known values into the equation and solve for the missing side length.