Hello, elmidge!

This is a 3-D problem . . . very hard to draw.

A cat sitting on the edge of a straight river bank spots a bird sitting in a tree directly across the river

and on the river's edge. .The angle of elevation from the cat to the bird is 15^{o}.

The cat then moves 25m along the river bank, and the angle elevation of the bird is 13^{i}.

How high is the tree?

This is the diagram with the first position of the cat and the tree.

The cat is at .Code:* B * | * 75^{o}| * | h * | * 15^{o}| C1 * - - - - - - - - * T h tan75^{o}

The bird is at .

The tree is:

Hence: .

This is the diagram with the second position of the cat and the tree.

The cat is atCode:B * | * | 77^{o}* h | * | * | 13^{o}* T * - - - - - - - - - - - * C2 h tan77^{o}

The bird is at

The tree is:

Hence:.

Looking down at the ground, this is the diagram.

Pythagorus: .Code:T * | * | * h tan75^{o}| * h tan77^{o}| * | * C1 * - - - - - - - - * C2 25

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Therefore: .