CHAPTER 9 : SOME APPLICATIONS OF TRIGONOMETRY

CBSE Class 10 Mathematics Standard — 2025 PYQs

PYQ Collection: Unique questions extracted from Series 30/1 to 30/6. Duplicate/repeated questions have been consolidated while retaining the relevant Series and Question Numbers.
Section A — Multiple Choice Questions (1 Mark)
1.
30/1/3 Q3 • 1 Mark
A kite is flying at a height of 150 m from the ground. It is attached to a string inclined at an angle of \(30^\circ\) to the horizontal. The length of the string is:
(A) \(100\sqrt{3}\) m
(B) 300 m
(C) \(150\sqrt{2}\) m
(D) \(150\sqrt{3}\) m
2.
30/3/1 Q19 • 1 Mark
Assertion (A): A ladder leaning against a wall stands at a horizontal distance of 6 m from the wall. If the height of the wall up to which the ladder reaches is 8 m, then the length of the ladder is 10 m.

Reason (R): The ladder makes an angle of \(60^\circ\) with the ground.
Assertion is true by Pythagoras theorem, but the Reason is not correct.
3.
30/4/1 Q10 • 30/4/2 Q12 • 1 Mark
A 30 m long rope is tightly stretched and tied from the top of a pole to the ground. If the rope makes an angle of \(60^\circ\) with the ground, the height of the pole is:
(A) \(10\sqrt{3}\) m
(B) \(30\sqrt{3}\) m
(C) 15 m
(D) \(15\sqrt{3}\) m
4.
30/6/1 Q13 • 30/6/3 Q4 • 1 Mark
A peacock sitting on the top of a tree of height 10 m observes a snake moving on the ground. If the snake is \(10\sqrt{3}\) m away from the base of the tree, then the angle of depression of the snake from the eye of the peacock is:
(A) \(30^\circ\)
(B) \(45^\circ\)
(C) \(60^\circ\)
(D) \(90^\circ\)
Section B — Very Short Answer Questions (2 Marks)
5.
30/4/1 Q22a • 30/4/2 Q22a • 30/4/3 Q21a • 2 Marks
A 1.5 m tall boy is walking away from the base of a lamp post which is 12 m high, at the speed of 2.5 m/sec. Find the length of his shadow after 3 seconds.
Section D — Long Answer Questions (5 Marks)
6.
30/2/1 Q32a • 30/3/3 Q33a • 5 Marks
Two ships are sailing in the sea on either side of a lighthouse. The angles of depression to the two ships as observed from the top of the lighthouse are \(60^\circ\) and \(45^\circ\), respectively. If the distance between the ships is \[ 100\left(\frac{1+\sqrt{3}}{\sqrt{3}}\right)\text{ m}, \] find the height of the lighthouse.
7.
30/2/1 Q32b • 30/2/3 Q33b • 5 Marks
The angles of depression of the top and bottom of an 8 m tall building from the top of a multi-storeyed building are \(30^\circ\) and \(45^\circ\), respectively. Find the height of the multi-storeyed building and the distance between the two buildings.
8.
30/2/2 Q35a • 5 Marks
The angle of elevation of a helicopter flying at a constant height of 2000 m from a point A on the ground is \(45^\circ\). After 15 seconds of flight, the angle of elevation changes to \(30^\circ\). Find the speed of the helicopter.

Take \(\sqrt{3}=1.732\).
9.
30/2/2 Q35b • 5 Marks
A 1.5 m tall girl is standing at some distance from a 30 m tall tower. The angle of elevation from her eyes to the top of the tower increases from \(30^\circ\) to \(60^\circ\) as she walks towards the tower. Find the distance she walked towards the tower.
Section E — Case Study Based Questions (4 Marks)
10.
30/1/1 Q38 • 30/1/3 Q36 • 4 Marks
Lighthouse Observation
Amruta is standing at a distance from the foot of a lighthouse and observes the top at \(60^\circ\). She then ascends 40 m to an observation deck and finds the angle of elevation to be \(45^\circ\).
(i) If \(CD=h\) metres, find distance \(BD\) in terms of \(h\). (1)

(ii) Find distance \(BC\) in terms of \(h\). (1)

(iii) (a) Find the height of the lighthouse \(CE\). Use \(\sqrt{3}=1.73\). (2)
OR
(iii) (b) If \(AC=100\) m, find distance \(AE\). (2)
11.
30/3/3 Q36 • 4 Marks
Ship Approaching Rock
A lighthouse is situated on a rock. The height of the lighthouse is 50 m. The angle of depression of a ship changes from \(30^\circ\) to \(45^\circ\) as it moves from point P to Q.
(i) Find the distance of the ship from the base of the lighthouse when it is at Q, where the angle of depression is \(45^\circ\). (1)

(ii) Find the measure of \(\angle PBA\) and \(\angle QBA\). (1)

(iii) (a) Find the distance \(PQ\) covered by the ship. (2)
OR
(iii) (b) If the ship takes 10 minutes to go from Q to A, calculate its speed in km/h. (2)
12.
30/4/2 Q37 • 4 Marks
Drone for Emergency
A drone is hovering at a height of 100 m above point Q. The angle of depression to the accident site P is \(30^\circ\).
(i) Represent the information through a labelled sketch. (1)

(ii) Find the distance between the ambulance at P and the accident site at the given moment. (1)

(iii) (a) Find the time taken if the angle changes from \(30^\circ\) to \(45^\circ\). (2)
OR
(iii) (b) If the drone moves to a point T and the angle of depression is \(60^\circ\), find the time. (2)
13.
30/6/1 Q38 • 4 Marks
Statue of Unity
A student uses an inclinometer to find the height of the Statue of Unity.

Situation I: The angle of elevation from Point A, which is \(80\sqrt{3}\) m from the base, is \(60^\circ\).
Answer the questions based on the given situation and observations to determine the height of the Statue of Unity and related distances/angles.
End of Chapter 9 PYQs
Total Unique Questions: 13
MCQs: 4  |  2 Marks: 1  |  5 Marks: 4  |  Case Study: 4