A. the sum of 30 and 42 B. The difference of 180 and (30+42)
C. Measure of angle 1 equal the measure of angle 2
D. The sum of angle 1 and 42 and 30

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.