Plzz answer the question

Answer:
x=29
Step-by-step explanation:
Use the triangle angle sum theorem which states that the interior angles of a triangle sum to 180. Notice the box in the corner of the triangle. This means that angle is 90 degrees.
61+90+x= 180. Combine like terms.
151+x=180. Subtract 151 from both sides.
x= 29