Answer:
x = 61
Explanation:
Before you begin to think about an answer, draw a line from the right angle to the 138 degree angle and the 144 degree angle. What you have created is a figure divided into 3 triangles. That means that the interior angles of the pentagon add up to 3 * 180 = 540 degrees.
Equation
x + 90 + 138 + 144 + 107 = 540
Solution
x + 479 = 540 Subtract 479 from both sides.
x + 479-479 = 540 - 479 Combine
x = 61