Answer:
12
Explanation:
To solve this, use the pythagreons theorm:
a^2+b^2=c^2
A and B are the side lengths, while is the hypotenuse, which in this case is 15 meters.
So lets plug in our values and solve for the missing length:
9^2+b^2=15^2
Square all the values except for the unknown:
81+b^2=225
Subtract from both sides to get b alone:
b^2=144
Take the square root of both sides so b^2 becomes b:
b=12
So your answer is 12!
Hope this helps!