Answer:
59 degrees
Explanation:
All the angles of a triangle (when combined) result in 180 degrees. This means that:
Angle 1 + angle 2 + angle 3 = 180 degrees.
We can see here that the shape here is a right triangle (noted by the square in the corner). This means that the angle set with the square is equal to 90. With this, we already have two of our angles! All we need is to set the equation using w, the angle you'll want to find:
31 + 90 + w = 180
w = 59
And there you are! Make sure to practice a few more problems like these to really get the hang of it. Good luck!