An airplane is flying between two towns at an altitude of 8km. one town is to the west of the plane and the other is to the east. the angle of depression to one town in de34grees and to the other town is 49degrees. what is the distance between the two towns

So this can be solve by solving the distance of the plane and the town to the west and also the distance of the plane to the town to the east.  
So the town with an angle of depression of 34 degrees
Let x be the distance of the plane and town  
Cos 34 = x / 8
x = 8 cos 34
x = 6.63 km  
So the town with an angle of depression of 49 degrees
Let y be the distance of the plane and town  
Cos 49 = y / 8
y = 8 cos 49
y = 5.25 km  
so the distance of the towns is 5.25 + 6.63 = 11.88 km