Answer:
128
Explanation:
Use A^2 + B^2 = C^2
You are trying to find (A^2) because you alredy know the longest side + one other side. So you rearange the rquation to C^2 - B^2 = A^2. Or 324 - 196 = root_A. In this case you leave it as that because you have the square root sign in your answer. But if yheir is no sign sqiare root it yourself to get the actual length of the last side