1) combined total of the degrees should be 360. Opposite angles are congruent. So if one angle is 80 so is the one opposite it. 360-160=200 Then divide by two because u need to find x which is one angle. X is 100 2) opposite sides are congruent so you set them equal. 31=2x-5 -5 -5 26=2x /2 /2 13=x 3) you set them equal because opposite angles are congruent x+3=4x-27 -x -x 3=3x-27 +27 +27 30=3x /3 /3 10 = x
