Answer:
The hypotenuse is 15.
Explanation:
The formula to calculate the hypotenuse is a^2+b^2+c^2. Since a=12 and b=9, we can plug those numbers in: 12^2+9^2=c^2.
12^2=144
9^2+81
144+81=225.
Next, we use the square root of 225, which is 15. 12^2+9^2=15^2.
So the hypotenuse is 15.