How do you solve 18 squared equals 6 squared plus b squared?

You may have the hypotenuse of a right triangle and the length of one side, and you're stuck finding the length of the other side. If you have 182 equals 62 plus b2, here's how to find the answer: 182 = 62 + b2 324 = 36 + b2 324 - 36 = b2 288 = b2 b = square root of 288 = about 16.97 Note that the square root of 288 is plus or minus 16.97, but when we're solving for the length of the side of a triangle, it can't have negative length, so we toss out the negative root and go with the positive one.