Triangles at the top.
Extreme left)
Finding the missing interior angle of the triangle,

On the other hand, such missing angle and angle x° are supplementary angles; thus,

The answer to the first triangle (extreme left) is x=117.
2) Similarly,

The answer to the second triangle is x=135
3)

The answer to the third triangle is x=34
4)

The answer to the fourth triangle (extreme right) is x=72