Two planes are heading towards an airport from opposite directions and at the same altitude. Pilot A informs that he is 2.3 km horizontally from the tower with an angle of depression of 20. Pilot B informs that he is at a horizontal distance of 3.7 km from the tower with an angle of depression of "".

a) Sketch the behavior of the problem.

b) Determine the angle "".

c) What is the height of plane A?

d) Determine two coterminal angles in the radial system of angle "".

Please, step by step.