three-dimensional applications

A hot-air balloon, B, is observed simultaneously from two points, P and Q, on horizontal ground. From P the bearing of B is 60 degrees at an angle of elevation of 45 degrees. From Q the bearing of B is 330 degrees at an angle of elevation of 60 degrees. The distance BQ is 800 m.

a) Draw a sketch showing the positions of P, Q and B.

b) Calculate the height of the balloon above the ground.

c) Calculate the bearing of Q from P.

Once again I need your help. (Thinking)(Thinking)

Time: 2 days.