Short answer: x = 40 Remark All you are concerned about is the bottom triangle. It is isosceles, so the two base angles are equal. You are 1 step away from finding x.
Step one Find he vertex angle (the top angle) of the triangle Let the vertex angle = V V + 70 + 70 = 180 Add the two 70s together. V + 140 = 180 Subtract 140 from both sides. V = 180 - 140 V = 40
Step Two Find x Since V and x are vertically opposite (you have to assume that or this question is unsolvable) then V = x x = 40 degrees
