# A triangle has sides A, B, and C. Sides A and B are of lengths 9 and 7, respectively, and the angle between A and B is (pi)/2 . What is the length of side C?

Feb 20, 2016

C = sqrt130 ≈ 11.4

#### Explanation:

Since the angle between A and B is $\frac{\pi}{2} \text{ then this is a right triangle with C , the hypotenuse.}$

hence C, can be found using $\textcolor{b l u e}{\text{ Pythagoras' Theorem}}$

${C}^{2} = {A}^{2} + {B}^{2} \Rightarrow {C}^{2} = {9}^{2} + {7}^{2} = 81 + 49 = 130$

rArr C = sqrt130 ≈ 11.4