Answer:
11.4017543
(round if you're supposed to)
Explanation:
It is a right triangle so you can use the pythagoreum theorem.
a(a) + b(b) = c(c)
a and b: legs
c: hypostenuse
9 and 7 are legs
the unknown is the hypostenuse
9(9) + 7(7) = c(c)
81 + 49 = c(c)
130 = c(c)
square root of 130 is 11.4017543
c(c) = 130
c = 11.4017543