Use the Pythagorean Theorem Calculator to find the hypotenuse of a right triangle from its two shorter sides.
How to Use
Enter side a and side b, which are the two sides that meet at the right angle, then press Calculate.
Formula in Plain Words
Square each shorter side, add the squares together, then take the square root of the total. That gives the hypotenuse, the longest side.
Worked Example
For side a = 3 and side b = 4, the squares are 9 and 16, their sum is 25, and the square root of 25 is 5, so the hypotenuse is 5.00.
FAQs
Does this work for any triangle?
No. It works only for a right triangle, which has one 90-degree angle.
Which side is the hypotenuse?
It is the side opposite the right angle, and it is always the longest side.
Can the sides be decimals?
Yes. Enter decimals as needed, and the hypotenuse is shown to two decimal places.