# If a triangle has side lengths 6, 8, 10 is it a right triangle?

Jun 8, 2015

We calculate the squares of the two littlest sides and add them :

6²+8²=36+64=100

We now calculate the square of the biggest side :

10²=100

They are equal, and thus, the triangle is a right triangle.

( AB²+BC²=AC² => $A B C$ is right in $B$ )

Jun 8, 2015

When the side lengths of a triangle are in the ratio 3: 4: 5, then it is a right triangle.
These sides are 6: 8: 10, then the triangle is a right one.