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From the top of a building. Badr saw a cow eating grass with a depression angle of 30o. If
the distance between the cow and the building is 21 m, find the height of the building!
Solution
1. From the question it is known that:
Distance from cow to building = 21 m
Depression angle = 30o
2. With the addition of auxiliary lines, it can be seen that the angle formed between the
observer to the cow and the observer to the building is a right angle. So that
The angle of the observer to the building is = 90 angle of the observer to the cow° −
The angle of the observer to the building is =90° − 30° = 60°
3. Choose a solution approach or strategy.
The relevant concept from the above problem is trigonometric ratios in right triangles.
Suppose that
t = building height
x = distance of cow to building
By using arithmetic operations, we get:
