Answer:
B
Step-by-step explanation:
here, we can use the pythagorean theorem. more info here: https://en.wikipedia.org/wiki/Pythagorean_theorem
formula: a^2+b^2=c^2
so we can apply the formula by doing this:
9^2+12^2=c^2
81+144=c^2
81+144=225
c=√225
c=15
solved
