Free Applications of Trigonometry 01 Practice Test - 10th Grade
Question 1
State whether the given statement is true or false:
The angle of depression is the angle between the line of sight of an observer below his horizontal line of sight.
True
False
SOLUTION
Solution : A
The angle of depression is the angle between the line of sight of an observer below his horizontal line of sight.
Question 2
State whether the given statement is true or false:
The angle of elevation is the angle between the line of sight of an observer below his horizontal line of sight.
True
False
SOLUTION
Solution : B
The angle of elevation is the angle between the line of sight of an observer above his horizontal line of sight.
Question 3
A circus artist is climbing a 30 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. The height of the pole, if the angle made by the rope with the ground level is 30∘
m.
SOLUTION
Solution :
The figure above represents the given situation.
In the given figure,
sin30∘=ABAC⇒AB=sin30∘×AC =AC2=302=15m.
Question 4
A circus artist is climbing a 30 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. Find the distance of the pole to the peg in the ground, if the angle made by the rope with the ground level is 30∘.
5 m
15√3 m
18 m
20 m
SOLUTION
Solution : B
The figure above represents the given situation.
From the given firgure,
cos30∘=BCAC⇒BC=AC×cos30∘=30√32
=15√3m
Question 5
A contractor plans to install two slides for the children to play in a park. For the children below the age of 5 years, she prefers to have a slide whose top is at a height of 2m and is inclined at an angle of 30∘ to the ground. What should be the length of the slide?
3 m
1.5 m
2 m
4 m
SOLUTION
Solution : D
The given situation can be represented by the figure below
In right-angled triangle ABC,
sin∠ABC=ACAB=12⇒sin30∘=2AB⇒AB=212⇒AB=4m∴Length of the slide is 4m.
Question 6
A contractor plans to install two slides for the children to play in a park for elder children. She wants to have a steep slide at a height of 6 m, and inclined at an angle of 60∘ to the ground. What should be the length of the slide (in m)?
3√3 m
5 m
4√3 m
6 m
SOLUTION
Solution : C
The above figure represents the given situation.
In the given right-agled triangle,
sin(∠ACB)=ABAC⇒sin60∘=6AC⇒AC=6√32=12√3=4√3 m∴length of slide=4√3 m
Question 7
A kite is flying at a height of 30 m above the ground. The string attached to the kite is temporarily tied to a point on the ground. The inclination of the string with the ground is 60∘. Find the length of the string, assuming that there is no slack in the string.
20√3 m
30 m
30√3 m
60 m
SOLUTION
Solution : A
The situation can be represented by the figure below:
In the given right-angled triangle:
sin(∠ACB)=ABAC
⇒sin60∘=ABAC
⇒AC=ABsin60∘=30√32=60√3=20√3
∴ Length of the string is 20√3 m.
Question 8
A kite is flying at a height of 30 m above the ground. The string attached to the kite is temporarily tied to a point on the ground. The inclination of the string with the ground is 30∘. Find the length of the string(in meters), assuming that there is no slack in the string.
60 m
40 m
30 m
20√3 m
SOLUTION
Solution : A
The given situation can be represented by the figure below
In the given right-angled triangle,
sin30∘=ABAC⇒AC=ABsin30∘=3012=60m
Therefore length of the string is 60 m.
Question 9
A 1.8 m tall man is standing at some distance from a 31.8 m tall building. The angle of elevation from his eyes to the top of the building increases from 30∘ to 60∘ as he walks towards the building. Find the distance he walked towards the building.
30 m
20√3 m
20 m
30√3 m
SOLUTION
Solution : B
The situation can be represented by the figure above,
tan(∠ACB)=ABBC⇒tan60∘=30BC⇒BC=30tan60∘=10√3m⇒tan(∠ADB)=ABBD⇒tan30∘=30BD⇒BD=301√3=30√3m⇒Distance walked=DC=BD−BC=30√3−10√3=20√3m
Question 10
A 1.8 m tall man is standing at some distance from a building. The angle of elevation from his eyes to the top of the building increases from 30∘ to 60∘ as he walks 20 m towards the building. Find the height of the building (in m).
10 m
20√3 m
20 m
(10√3 + 1.8) m
SOLUTION
Solution : D
The situation can be represented by the figure above.
tan(∠ACB)=ABBC⇒BC=ABtan60∘.....(1)tan(∠ADB)=ABBD⇒tan30∘=ABBC+CD⇒BC+CD=ABtan30∘.....(2) on subtracting equation(1) from (2)⇒CD=ABtan30∘−ABtan60∘⇒AB=10√3
Hence, the height of the building is
= AB + BG = (10√3+1.8)m.