Trigonometry word problem

A hang glider is observed from a field due east at an angle of elevation of 50 degree. The hang glider is 2 km away from the observer at this first field. The angle of elevation from a second field is 23 degree. The second field is 3.5 km away from the first at a bearing of 155 degree. How high is the hang glider.

This part is really confuses me----->The angle of elevation from a second field is 23 degree. The second field is 3.5 km away from the first at a bearing of 155 degree. How high is the hang glider.

Please help. Thank you