Answer:
20 degrees
Explanation:
we can consider 33 to be the radius of a circle.
31 would then be the cos of the angle in that circle.
the regular cos function is defined for the standard circle with radius 1. so, that would be multiplied by 33 for this circle here.
31 = cos(?) × 33
cos(?) = 31/33 = 0.9393...
? = 20.05 ≈ 20 degrees