Answer:
a 44°
Step-by-step explanation:
Think of the right triangle formed by the beam, the ground, and the wall.
The beam is the hypotenuse. For the angle between the ground and the beam, call it angle A, the 13.9 ft side is the opposite leg. The trig ratio that relates the opposite leg and the hypotenuse is the sine.
sin A = opp/hyp
sin A = 13.9/20
sin A = 0.695
A = sin^-1 0.695
A = 44°
