C.) 68 Why? a triangle has 180 degrees. The tics denote the sides being equal, which means the opposite angles are equal, too. To get the remaining subtract it from 180... 180- 2(56) =68 degrees
A triangle should add up to 180 degrees. So subtract 56 from 180 and get 124. This is an isosceles triangle so 2 sides have the same degree, which would be the bottom 2 sides in this case so 124-56=68, the answer is x=68. You can check by adding them all up:56+56+68=180 so this is correct.