# How do you find the missing side of the right triangle with legs: a = 5, b = 12?

##### 2 Answers

**Assuming the missing side, c, is the hypotenuse**

by the Pythagorean Theorem

**If the missing side, c, is not the hypotenuse**

then b, the longer side must be the hypotenuse, and

by the Pythagorean Theorem

or

Use Pythagoras theorem: "The square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides"

So the hypotenuse of your triangle has length

You have probably encountered the 3-4-5 triangle. The 5-12-13 triangle is part of the same sequence of right angled triangles with integer length sides:

If

are the lengths of the sides of a right angled triangle.