What is the degree of the sin of .19

Asap! i'm not good math and i'm lost.

Solve this problem! extra ! 3025/5.5 = a/90.75

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )