complementary angles, heights and distances, applications of trigonometry - One Line Questions
1.
What is the value of tan(45°)? —
1
2.
What is the value of sin²(θ) + cos²(θ)? —
1
3.
If sin(θ) = cos(θ), then θ is: —
45 degrees
4.
If the angle of elevation of the sun is 30 degrees, the ratio of the height of a vertical object to the length of its shadow is: —
1 : √3
5.
What is the value of sin(30°)? —
1/2
6.
What is the value of cos(60°)? —
1/2
7.
The angle of elevation of the top of a tower from a point A on the ground is 45 degrees. From another point B, 10 meters above A and on the line joining A to the foot of the tower, the angle of elevation is 60 degrees. What is the height of the tower? —
10(√3 + 1) meters
8.
The angle of elevation of the top of a building from a point P on the ground is 30 degrees. If the point P is moved 20 meters closer to the building, the angle of elevation becomes 60 degrees. What is the height of the building? —
20√3 meters
9.
The angle of elevation of the top of a cliff from a boat is 30 degrees. If the boat sails 200 meters further away from the cliff, the angle of elevation becomes 15 degrees. What is the height of the cliff? —
200√2 meters
10.
A man can see the top of a tower at an angle of elevation of 30 degrees. If he walks towards the tower a distance of 100 meters, the angle of elevation becomes 60 degrees. What is the initial distance of the man from the tower? —
200 meters
11.
From the top of a cliff 100 meters high, the angle of depression of a boat is 30 degrees. How far is the boat from the foot of the cliff? —
100√3 meters
12.
Two persons are on opposite sides of a tower 100 m high. They observe the angle of elevation of the top of the tower to be 30 degrees and 45 degrees respectively. What is the distance between the two persons? —
100(1 + 1/√3) meters
13.
A balloon is observed from two points on the ground, diametrically opposite to each other, on a straight road passing below the balloon. The angles of elevation are 30 degrees and 60 degrees. If the height of the balloon is 100 meters, what is the distance between the two points? —
100(1/√3 + √3) meters
14.
A man stands 100 meters away from a lighthouse. The angle of elevation of the top of the lighthouse from the man's eyes is 30 degrees. If the man's height is 1.5 meters, what is the height of the lighthouse? —
50√3 + 1.5 meters
15.
If sin(2θ) = cos(θ), and 2θ and θ are acute angles, then θ is: —
30 degrees
16.
The angle of elevation of the sun is 30 degrees. If the length of the shadow cast by a vertical pole is 45 meters, what is the height of the pole? —
45/√3 meters
17.
A boy is flying a kite. The string of the kite is 150 meters long. The angle of elevation of the kite from the boy's hand is 60 degrees. If the boy's hand is 1 meter above the ground, what is the height of the kite from the ground? —
75√3 + 1 meters
18.
If tan(θ) = 5/12, what is the value of sin(θ) + cos(θ)? —
17/13
19.
A vertical pole of length 6 meters casts a shadow of length 4 meters when the sun's altitude is θ. What is the value of tan(θ)? —
3/2
20.
A flagstaff stands on the top of a building. At a point on the ground 20 meters away from the base of the building, the angle of elevation of the top of the flagstaff is 60 degrees and the angle of elevation of the base of the flagstaff is 45 degrees. What is the height of the flagstaff? —
20(√3 - 1) meters
21.
If tan(θ) = 3/4, what is the value of sin(θ) in a right-angled triangle? —
3/5
22.
If sin(θ) = 3/5, what is the value of cos(θ) in a right-angled triangle? —
4/5
23.
If sin(θ) = 1/2, what is the value of θ? —
30 degrees
24.
If cos(θ) = √3/2, what is the value of θ? —
30 degrees
25.
If tan(θ) = 1, what is the value of θ? —
45 degrees
26.
In a right-angled triangle ABC, with the right angle at B, if angle C = 30 degrees, then angle A is: —
60 degrees
27.
If tan(θ) = 1/√3, what is the value of θ? —
30 degrees
28.
The angle of elevation of the top of a tower from a point on the ground, which is 30 meters away from the foot of the tower, is 60 degrees. What is the height of the tower? —
30√3 meters
29.
If two angles are supplementary and one is twice the other, what are the angles? —
60° and 120°
30.
A vertical tree is broken by the wind. The broken part makes an angle of 30 degrees with the ground and touches the ground at a distance of 30 meters from the foot of the tree. What was the original height of the tree? —
60√3 meters
31.
If angle A and angle B are complementary, and angle A = 40 degrees, what is the measure of angle B? —
50 degrees
32.
A kite is flying at a height of 60 meters above the ground. The string attached to the kite makes an angle of 60 degrees with the horizontal. What is the length of the string? —
120/√3 meters
33.
If sec(θ) = 13/5, what is the value of tan(θ) in a right-angled triangle? —
12/5
34.
If cot(θ) = 5/12, what is the value of cosec(θ) in a right-angled triangle? —
13/12
35.
If the angle of elevation of the top of a tower from a point 100 meters away from its base is 45 degrees, what is the height of the tower? —
100 meters
36.
What is the minimum height from which an object must be dropped so that its speed upon impact is 19.6 m/s? (g = 9.8 m/s²) —
19.6 meters
37.
If two angles are complementary, their sum is: —
90 degrees
38.
Two angles are supplementary if their sum is: —
180 degrees
39.
If tan(A) = cot(B), then A + B is equal to: —
90 degrees
40.
A ladder of length 10 meters is leaning against a wall. If the foot of the ladder is 6 meters away from the base of the wall, what is the angle the ladder makes with the ground? —
arccos(3/5)
41.
Two observers are on the same side of a tower, at distances x and y (y > x) from its base. The angles of elevation of the top of the tower are α and β respectively. If x = 100m and y = 200m, and α = 60°, what is β? —
arctan(2/√3)
42.
A bird is sitting on the top of a tree 15 meters high. It flies off and lands on the ground at a point 20 meters away from the base of the tree. What is the angle of depression from the bird's initial position to the landing spot? —
arctan(3/4)
43.
The angle of depression of an object from a point is equal to the angle of elevation of the point from the object, provided the horizontal line is the same. This is a property related to: —
Alternate interior angles
44.
If angle A = 50 degrees and angle B = 40 degrees, then A and B are: —
Complementary angles
45.
If the angle of elevation of the sun increases from 30 degrees to 60 degrees, the length of the shadow of a vertical pole: —
Decreases
46.
What is the value of sin(90° - θ)? —
cos(θ)
47.
What is the value of cos(90° - θ)? —
sin(θ)
48.
Which trigonometric ratio is used to find the height of an object when the angle of elevation and the distance from the object are known? —
Tangent
49.
If A and B are complementary angles, then which of the following is true? —
tan(A) = cot(B)
50.
In a right-angled triangle, if one of the non-right angles is θ, the other non-right angle is: —
90 - θ