An airplane begins its descent with an average speed of 240 mph at an angle of depression of 4°. how much altitude will the plane lose in 5 min. round to the nearest tenth of a mile.

Distance=speed*time
distance covered by plane in 5 min will be:
distance=240×5/60=20 miles
thus the altitude lost will be:
sin θ=opposite/hypotenuse
sin 4=h/20
h=20sin 4
h=1.395 miles~1.4 miles