Question

A person standing on the bank of a river, observes that the angle subtended by a tree on the opposite bank has measure 60. When he retreats 20 m from the bank, he finds the angle to have measure 30. Find the height of the tree and the breadth of the river.

Answer 1

Let, the height of the tree is h m.

and the depth of the river is x m.

We,know the angle 60 and 30 degree respectively.

On solving we got x = 10 m and h = 10/√3 m .

See the attachment.