Please please help!! it’s geometry and im struggling really badly

Find the cosine function that is represented in the graph.

Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?

1) what is the measure of the exterior angle, ∠uvw ? 2) in triangle man, what is the measure of the exterior angle at n (in degrees)?