The Pythagorean theorem is a useful way to find missing sides in right triangles.

It tells us that in a right triangle, the square of the longest side (called the hypotenuse, $c$) is equal to the sum of the squares of the other two sides ($a$ and $b$).

Here’s the formula:

$c^2 = a^2 + b^2$

Let’s break down how to use it:

1. Finding the Hypotenuse: If we know the lengths of both shorter sides ($a$ and $b$), we can find the hypotenuse ($c$) by changing the formula a bit:

   $c = \sqrt{a^2 + b^2}$

2. Finding a Side: If we know the length of the hypotenuse and one of the shorter sides, we can find the other side. For example, if we know $c$ and $a$, we can find $b$ like this:

   $b = \sqrt{c^2 - a^2}$

Using the Pythagorean theorem helps us solve everyday problems that involve right triangles, like figuring out how high something is or how far apart two points are!