7. Find the width of the river

A person in the helicopter flying at the height of 621 \(m\) above the river observes two objects lying opposite to each other on either bank of a river. The angles of depression of the objects are 30\(^{\circ}\) and 45\(^{\circ}\). Then, the width of the river is 1696.5721694.5721695.5721697.572 \(m\).

 

(Note: Substitute \(\sqrt{3} = 1.732\) if necessary.)