The hypotenuse of a 45°-45°-90° triangle measures 10 sqrt 5 in. what is the length of one leg of the triangle?

There is this specific ratio for 45-45-90 triangles where the length of the hypotenuse is radical 2 times as long as a leg. With this in mind, we can create an equation where the length of one leg is represented with the variable x.

x = 10 
divide both sides by  
x = 10 /  
x = 10 /2
x = 5 

The length of one leg is 5