Question

From the diagram below, of the distance between the tree and point B is 125 meters, and the angle of depression from the top of the tree to point B is 46 degrees, how tall is the tree in meters? (round to the nearest whole meter)

Answer 1

a. 129 meters

Explanation:

The given parameters of the tree and the point B are;

The horizontal distance between the tree and point B, x = 125 meters

The angle of depression from the top of the tree to the point B, θ = 46°

Let h represent the height of the tree

The horizontal line at the top of the tree that forms the angle of depression with the line of sight from the top of the tree to the point B is parallel to the horizontal distance from the point B to the tree, therefore;

The angle of depression = The angle of elevation = 46°

By trigonometry, we have;

tan(θ) = h/x

∴ h = x × tan(θ)

Plugging in the values of the variables gives;

h = 125 × tan(46°) ≈ 129.44

The height of the tree, h ≈ 129 meters