13. Calculate the distance between the two jet planes

A jet plane is flying at the height of 2000 $m$ from the ground, and another jet plane passes directly beneath the first jet plane. The angle of elevation from a point on the ground to the first and second jet plane are 62$^{\circ}$ and $45^{\circ}$, respectively. The distance between the two jet planes is

 

(Use $tan \ 62^{\circ} = 1.881$)