The answer is 119. 180-112= 68 which is the value of c, 180-68-51= 61 which is the value of a. in order to find b you need to subtract 180 by a (61) and you get 119
Angle C and the outside angle are supplementary meaning they equal 180°. 180-112=68, therefore angle C is 58°. All angles of a triangle are equal to 180°. 51+68=119, 180-119=61 therefore angle A is 61°. Angle A and B are also supplementary angles, 180-61=119, so angle B is 119°.
