Question 873522
(leg)^2 + (leg^2 = (hypotenuse)^2

Let x = the missing leg


x^2 + 5^2 = 15^2

x^2 + 25 = 225

x^2 = 225-25

x^2 = 200

Take square root of both sides.

Let sqrt = square root for short

sqrt(x^2) = sqrt(200)

x = sqrt(100) times sqrt(2)

x = 10*sqrt(2)

The missing leg has a length of 10*sqrt(2)