Students often find the concept of inverse trig functions confusing. Inverse cosine is only defined in Quadrants 1 and 2 and Inverse Sin is only defined in Quadrants 1 and 4. However, it is possible to find angles that work for these inverse trig functions in all 4 quadrants.
This worksheet forces students to find all 4 reference angles and to realize that the absolute value of their sin and cosine are exactly the same in all cases.
This is the free version. In the future look for this to be converted into a puzzle. Hope you enjoy and I hope this helps your students master reference angles and inverse trig functions.