The hypotenuse of a 45-45-90 triangle has a length of 10 units. what is the length of one of its legs?

When a triangle is a 45-45-90 triangle, the following rules apply:

-the 2 legs are equal lengths
- the length of the hypotenuse is: the square root of 2 x the length of a leg.
- the length of the leg is: hypotenuse divided by the square root of 2.

if the hypotenuse is 10, then 10 divided by the square root of 2 is how you find the leg.
the square root of 2 is 1.41421356237. 
10 divided by 1.41421356237 is 7.07106781188, which can be rounded to about 7.1. The length of one leg is about 7.1 units!