A dog that has been tethered with a 20-foot lead makes the path shown here.
If the length of the path is 45 feet, the measure of the angle 9 is __ radians.
20 ft
De
45 ft.

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! )