Reference angle for 11pi/4

Allie is playing basketball. she takes a shot 24 ft away from the basket. when the ball is 4 ft away from her, it is at height of 10 ft above the floor. the ball reachs its highest point of 18 ft above the floor, when it is 12 ft away from her? a. find the value of a b. if the hoop is 10 ft high, how close would allie to be to make the basketball