Question

From a position 3.5 m above ground level in a building, an an observer measures the angle of elevation of the top of a flagpole to be 48°, and the angle of depression of the foot of the flagpole to be 35°.

How far away from the building is the flagpole?​

Answer 1

2.73 meters away from the building.

Explanation:

To find the distance from the building to the flagpole, we can use the tangent function. Let's call the distance from the building to the flagpole "d".

The tangent of the angle of elevation is equal to the height of the flagpole (h) divided by the distance from the building to the flagpole (d):

tan 48° = h / d

The tangent of the angle of depression is equal to the distance from the building to the flagpole (d) divided by the height of the observer (3.5 m):

tan 35° = d / 3.5

We can use these two equations to find the value of d. Solving the first equation for h:

h = tan 48° * d

And substituting that into the second equation:

tan 35° = d / (tan 48° * d / 3.5)

Solving for d:

d = 3.5 * tan 35° / tan 48°

Using a calculator, we can find that:

d = 3.5 * tan 35° / tan 48° = 3.5 * 1.3602668 / 1.7415198 = 2.73 m

So the flagpole is 2.73 meters away from the building.