Hi (7x+6) + 10x + Z = 180 17x + 6 + Z = 180 Z = Re TY: Must be 'more to the story' IF X = Z, yes, Z = 55° Z X Y X + Y + Z x 174-17x 7X + 6 10X 1 157 13 10 180 2 140 20 20 180 3 123 27 30 180 4 106 34 40 180 5 89 41 50 180 6 72 48 60 180 7 55 70 180