Avani is trying to find the height of a radio antenna on the roof of a local building. She stands at a horizontal distance of 21 meters from the building. The angle of elevation from her eyes to the roof ((point AA)) is 27^{\circ} ∘ , and the angle of elevation from her eyes to the top of the antenna ((point BB)) is 37^{\circ} ∘ . If her eyes are 1.54 meters from the ground, find the height of the antenna ((the distance from point AA to point BB)). Round your answer to the nearest tenth of a meter if necessary.
The answer is 5.1.