Answer:
12 inches
Step-by-step explanation:
The Pythagorean's theorem states that a triangle's hypotenuse's length is equal to a^2+b^2=c^2.
9 is a, b is the length, and c is the 15.
9^2+b^2=225
225-81=144
The square root of 144 is 12, therefore 12 inches is the length.
