21. Determine the altitude of the helicopter

A passenger in the helicopter spots a ship and a blue whale at an angle of 30$^{\circ}$ and 45$^{\circ}$, respectively. If the ship is exactly behind the whale, then the distance between them is 101 $m$, then the altitude of the helicopter above the sea level is 137.98136.98138.98139.98 $m$. (Use $\sqrt{3} = 1.732$)