#1**-1 **

Let's draw a line that is parallel to the top and bottom passing through X.

The angle next to 25degrees is 180-25 = 155, and the one by 30 is 180-30 = 150.

Hey we don't need to know that!

The "chopped off" angle part on the bottom of the middle line, is also 25, and the top part is 30

Thus X = 30+25 = 55 degrees.

hugomimihu Jun 22, 2020