Two observers 5000m apart, standing at A and B measure the angle of elevation to a weather balloon at H as 47degrees and 71degrees. Find the height of the weather balloon correct to the nearest metre.

Not certain about my answer to this question. This is what i came up with

a = c

Sin A Sin C Sin71= opposite

5000m*Sin47=a Hypotenuse

Sin62 Sin71=X

5000m*Sin47=a 4142sin71

a=4142 X= 3916

Is it right ?