NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 8: Introduction to Trignometry and Its Applications - Exercise 8.1
Question 15

Question.  15

A pole 6 m high casts a shadow \(2\sqrt{3}\) m long on the ground. The Sun’s elevation is

(A)

\(60^\circ\)

(B)

\(45^\circ\)

(C)

\(30^\circ\)

(D)

\(90^\circ\)

Handwritten Notes

A pole 6 m high casts a shadow \(2\sqrt{3}\) m long on the ground. The Sun’s elevation is 1

Video Explanation:

Detailed Answer with Explanation:

Step 1: Draw a right-angled triangle.

- The pole is the vertical side (opposite side) = \(6\,\text{m}\).

- The shadow is the horizontal side (adjacent side) = \(2\sqrt{3}\,\text{m}\).

- The angle of elevation of the Sun is \(\theta\) (the angle between the sunlight and the ground).

Step 2: Use the definition of tangent.

\( \tan\theta = \dfrac{\text{opposite side}}{\text{adjacent side}} \)

Here, opposite = height of pole = \(6\,\text{m}\), adjacent = shadow length = \(2\sqrt{3}\,\text{m}\).

Step 3: Substitute the values.

\( \tan\theta = \dfrac{6}{2\sqrt{3}} \)

Step 4: Simplify the fraction.

\( \dfrac{6}{2\sqrt{3}} = \dfrac{3}{\sqrt{3}} = \sqrt{3} \)

Step 5: Recall the trigonometric ratio.

\( \tan 60^\circ = \sqrt{3} \)

Step 6: Therefore, \( \theta = 60^\circ \).

Final Answer: The Sun’s elevation is \(60^\circ\).

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 8: Introduction to Trignometry and Its Applications – Exercise 8.1 | Detailed Answers