All Exams Test series for 1 year @ ₹349 only
Question

A tower stands vertically on the ground. From a point on the ground which is 28.6 m away from the foot of a tower, the angle of elevation of the top of the tower is found to be 45°. Find the height of the tower.

The correct answer is
28.6 m

Tower Height Calculation Using Trigonometry

The problem involves finding the height of a tower given the distance from its base and the angle of elevation to its top. This can be solved using basic trigonometry in a right-angled triangle.

Identifying the Triangle Components

Consider the right-angled triangle formed by:

  • The tower's height (opposite side to the angle of elevation). Let this be '$h$'.
  • The distance from the ground point to the foot of the tower (adjacent side to the angle of elevation). This is given as 28.6 m.
  • The line of sight from the ground point to the top of the tower (hypotenuse).

The angle of elevation is given as 45°.

Applying the Tangent Function

The trigonometric function relating the opposite side, adjacent side, and the angle is the tangent:

$ \tan(\text{angle}) = \frac{\text{Opposite}}{\text{Adjacent}} $

Substituting the known values:

$ \tan(45^\circ) = \frac{h}{28.6 \text{ m}} $

Calculating the Tower Height

We know that $\tan(45^\circ) = 1$. Therefore, the equation becomes:

$ 1 = \frac{h}{28.6 \text{ m}} $

Solving for '$h$':

$ h = 1 \times 28.6 \text{ m} $

$ h = 28.6 \text{ m} $

The height of the tower is 28.6 m.

Was this answer helpful?

Important Questions from Heights and Distances

  1. If x is the distance of P from the bottom of the pillar, then consider the following statements :

    1. x can take two values which are in the ratio 1 : 3

    2. x can be equal to the height of the flagstaff

    Which of the statements given above is/are correct?

  2. What is a possible value of tan θ ? 

  3. A vertical tower standing on a levelled field is mounted with a vertical flag staff of length 3 m. From a point on the field, the angles of elevation of the bottom and tip of the flag staff are 30° and 45° respectively. Which one of the following gives the best approximation to the height of the tower?

  4. Two poles are 10 m and 20 m high. The line joining their tops makes an angle of 15° with the horizontal. The distance between the poles is approximately equal to

  5. The angle of elevation of the top of a tower from a point 20 m away from its base is 45 °. What is the height of the tower?

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App