Question

Solve for x and justify your answer ​

Answer 1

The answer is 51°.

The top two lines are parallel to each other. Therefore alternate interior angles theorem applies. The bottom right corner that is underneath the line (for lack of a better description) is also 58°.

We also know that a triangle equals 180°. So 58+71= 129°.

So to find that missing angle we subtract 129 from 180 to get the 51°.