The polygon given in the question has three (3) sides, so it is a triangle.
The sum of interior angles of a triangle = 180 degrees
Hence, the sum of the interior angles of the shape is 180 degrees
To solve for x:
34 + 38 + x = 180 (sum of angles in a triangle is 180)
72 + x = 180
subtract 72 from both sides
x = 180 - 72
x = 108 degrees
