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!

A’b’c’ are the coordinates to the new location of the transformed triangle abc. find the distance between the coordinates points to use for your calculations.