a lamppost, cab, bent at point a after a storm. the tip of the lamppost touched the ground at point c, as shown below:

triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

what is the height, in feet, of the portion ab of the lamppost?

20 divided by tan 55 degrees
20 cos 55°
20 tan 55°
20 divided by cos 55 degrees