An airplane is sighted at the same time by two ground observers who are 5 miles apart and both directly west of the airplane. they report the angles of elevation as 14° and how high is the airplane? round to the nearest hundredth of a mile.

The complete question: 
An airplane is sighted at the same time by two ground observers who are 5 miles apart and both directly west of the airplane. they report the angles of elevation as 14° and 30° how high is the airplane? round to the nearest hundredth of a mile.

Check the diagram of the situation in the picture attached.

First, we are going to use the law of sines to find the measure of side  in triangle ABC:




Next, we are going to use the trig function Sine in triangle BCD to find the height, , of the plane:




We can conclude that the plane is 2.19 miles high. 

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)