Answer: Choice B) 5 units
===================================================
Explanation:
This is a 45-45-90 triangle. The legs are both the same (both 5) and the hypotenuse is in the form x*sqrt(2) where x = 5 is the length of each leg. You can use the pythagorean theorem to solve for b as shown below
a^2 + b^2 = c^2
5^2 + b^2 = (5*sqrt(2))^2
25 + b^2 = 50
b^2 = 50-25
b^2 = 25
b = sqrt(25)
b = 5
So this proves the two legs a = 5 and b = 5 are the same. This is an isosceles right triangle.
