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

A 5-foot person casts a 4-foot shadow. At the same time, a tree casts a 20-foot shadow. How tall is the tree?

This question was previously asked in
SSC CGL 2025 Tier 1 Question Paper (25-Sep-2025) (Shift 3)
The correct answer is
25 feet

Tree Shadow Height Calculation

This problem uses the concept of similar triangles or direct proportion. Since the sun's rays are parallel at a given time, the ratio of an object's height to its shadow's length remains constant.

Proportion Setup

Let $H_{person}$ be the height of the person and $S_{person}$ be the length of the person's shadow. Let $H_{tree}$ be the height of the tree and $S_{tree}$ be the length of the tree's shadow.

The proportion is set up as:

$ \frac{H_{person}}{S_{person}} = \frac{H_{tree}}{S_{tree}} $

Applying Values

Given values are:

  • Person's height ($H_{person}$): 5 feet
  • Person's shadow ($S_{person}$): 4 feet
  • Tree's shadow ($S_{tree}$): 20 feet

Substitute these into the proportion:

$ \frac{5 \text{ feet}}{4 \text{ feet}} = \frac{H_{tree}}{20 \text{ feet}} $

Solving for Tree Height

To find the tree's height ($H_{tree}$), we solve the equation:

$ H_{tree} = \frac{5}{4} \times 20 \text{ feet} $

Calculate the result:

$ H_{tree} = 5 \times \left(\frac{20}{4}\right) \text{ feet} $ $ H_{tree} = 5 \times 5 \text{ feet} $ $ H_{tree} = 25 \text{ feet} $

Result

The height of the tree is 25 feet.

Was this answer helpful?

Similar Questions

  1. The angles of elevation of the top of a cliff from two points on the ground, $200\text{ m}$ apart, and on opposite sides of the cliff, are $30^{\circ}$ and $45^{\circ}$. What is the height of the cliff?
  2. A kite is soaring at an altitude of 75 meters above the ground, with its string temporarily secured to a point on the ground. The angle of elevation of the string relative to the ground is 30 degrees. Given that the string remains taut, what is the length of the string?
  3. A man observes the top of a pole with an angle of elevation of 45°. He walks 15 m towards the pole, and the angle of elevation becomes 60°. What is the height of the pole?

  4. Two ships positioned on opposite sides of a lighthouse observe the angles of elevation to the top of the lighthouse, which are 30° and 45° respectively. Given that the height of the lighthouse is 100 meters, determine the distance between the two ships.


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?
Test Series
SSC CGL img
SSC
SSC CGL (Tier I + Tier II) 2026 Mock Test Series - Latest Pattern
1736 Tests 6 Tests Free
1844 Attempts
4.2(846)
English, Hindi

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