A damsel is in distress and is being held captive in a tall tower far far away. Her knight in shinning armor is on the ground below with a ladder. When the knight stands 15 feet from the base of the tower and looks up at his precious love, the angle of elevation he makes with the ground to her window is 60°
60
°
. How far up on the tower does the ladder have to be to reach her? Draw a detailed picture for extra extra credit, along with your work.