1) a and b are the shortest 2 sides, and c is the longest side, and we assume that this is a right triangle. Then 7^2 + 11^2 = c^2, or c^2 = 49 + 121 =170. c is then sqrt(170) (answer)
2) b is the hypo and a and c are the 2 legs. Then 11^2 = 7^2 + c^2, and 121-49 = c^2, so that c = sqrt(72), or sqrt(36)*sqrt(2) = 6*sqrt(2) (answer)