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# Frank solutions for Class 10 Mathematics chapter 22 - Heights and Distances

## Chapter 22: Heights and Distances

Exercise

#### Chapter 22: Heights and Distances Exercise Exercise solutions [Page 22]

Exercise | Q 1 | Page 22

The distance of the gate of a temple from its base is sqrt(3) times it height. Find the angle of elevation of the top of the temple.

Exercise | Q 2 | Page 22

The angle of elevation of the top of a vertical cliff from a point 30 m away from the foot of the cliff is 60°. Find the height of the cliff.

Exercise | Q 3 | Page 22

A vertical pole is 90m high and the length of its shadow is 90sqrt(3). what is the angle of elevation of the sun  ?

Exercise | Q 4 | Page 22

The length of the shadow of a pillar is 1/sqrt(3) times the height of the pillar . find the angle of elevation of the sun .

Exercise | Q 5 | Page 22

Find the length of the shadow cast by a tree 60 m high when the sun's altitude is 30^circ.

Exercise | Q 6 | Page 22

An aeroplane takes off at angle of 30^circ with the ground . Find the height of the aeroplane above the ground when it has travelled 386m without changing direction .

Exercise | Q 7 | Page 22

A kite tied to a string makes an angle of 60° with the ground. Find the perpendicular height of the kite if the length of its string is 250 m.

Exercise | Q 8 | Page 22

The topmost branch of a tree is tied with a string attached to a pole in the ground. The length of this string Is 200m and it makes an angle of 45° with the ground. Find the distance of the pole to which the string is tied from the base of the tree.

Exercise | Q 10 | Page 22

A 10 m high pole is kept vertical by a steel wire. The wire is inclined at an angle of 40° with the horizontal ground. If the wire runs from the top of the pole to the point on the ground where Its other end is fixed, find the lenqth of the wire.

Exercise | Q 11 | Page 22

A ladder rests against a tree on one side of a street. The foot of the ladder makes an angle of 50° with the ground. When the ladder is turned over to rest against another tree on the other side of the street it makes an angle of 40° with the ground. If the length of the ladder is 60m, find the width of the street.

Exercise | Q 12 | Page 22

Due to a heavy storm, a part of a banyan tree broke without separating from the main. The top of the tree touched the ground 15 m from the base making an angle of 45° with the ground. Calculate the height of the tree before it was broken.

Exercise | Q 13 | Page 22

The top of a palm tree having been broken by the wind struck the ground at an angle of 60° at a distance of 9m from the foot of the tree. Find the original height of the palm tree.

Exercise | Q 14 | Page 22

Find the angle of depression from the top of a 140m high pillar of a milestone on the ground at a distance of 200m from the foot of the pillar.

Exercise | Q 15 | Page 22

The height of an observation tower is 180m above sea level. A ship coming towards the tower is observed at an angle of depression of 30°. Calculate the distance of the boat from the foot of the observation tower.

Exercise | Q 16 | Page 22

The angles of depression and elevation of the top of a 12m high building from the top and the bottom of a tower are 60° and 30° respectively. Find the height of the tower, and its distance from the building.

Exercise | Q 17 | Page 22

A flagstaff stands on a vertical pole. The angles of elevation of the top and the bottom of the flagstaff from a point on the ground are found to be 60° and 30° respectively. If the height of the pole is 2.5m. Find the height of the flagstaff.

Exercise | Q 18 | Page 22

A vertical tow er stands on a horizontal plane and is surmounted by a flagstaff of height 7m. From a point on the plane the angle of elevation of the bottom of the flagstaff is 30° and that of the top of the ft agstaff is 45°. Find the height of the tower.

Exercise | Q 19 | Page 22

The angle of elevation of the top of an unfinished tower at a point 150 m from its base is 30°. How much higher must the tower be raised so that its angle of elevation at the same point may be 60°?

Exercise | Q 20 | Page 22

A 1.4m tall boy stands at a point 50m away from a tower and observes the angle of elevation of the top of the tower to be 60°. Find the height of the tower.

Exercise | Q 21 | Page 22

A boy is 1.54 m tall. Standing at a distance of 3m in front of a 4.54 m high wall he can just manage to see the sun. Find the angle of elevation of the sun.

Exercise | Q 22 | Page 22

An observer, 1.5m tall, is 28.5m away from a tower 30m high. Determine the angle of elevation of the top of the tower from his eye.

Exercise | Q 23 | Page 22

A boy is standing on the ground and flying a kite with 100m of sting at an elevation of 30°. Another boy is standing on the roof of a 10m high building and is flying his kite at an elevation of 45°. Both the boys are on opposite sides of both the kites. Find the length of the string that the second boy must have so that the two kites meet.

Exercise | Q 24 | Page 22

The horizontal distance between two trees of different heights is 100m. The angle of depression of the top of the first tree when seen from the top of the second tree is 45°. If the height of the second tree is 150m, find the height of the first tree.

Exercise | Q 25 | Page 22

Two persons standing on opposite sides of a tower observe the angles of elevation of the top of the tower to be 60° and 50° respectively. Find the distance between them, if the height of the tower is 80m.

Exercise | Q 26 | Page 22

The angles of depression of two cars on a straight road as observed from the top of a 42m high building are 60° and 75° respectively. Find the distance between the cars if they are on opposite sides of the building.

Exercise | Q 27 | Page 22

An aeroplane at an altitude of 200 m observes the angles of depression of opposite points on the two banks of a river to be 45° and 60°. Find the width of the river.

Exercise | Q 28 | Page 22

An observer point for ships moving in the sea 500m above the sea level. The person manning this point observes the angle of depression of twc boats as 45° and 30°. Find the distance between the boats when they are on the same side of the observation point and when they are on opposite sides of the observation point.

Exercise | Q 29 | Page 22

Two boats approaching a light house in mid sea from opposite directions observe the angle of elevation of the top of the light house as 30° and 45° respectively. If the distance between the two boats is 150m, find the height of the light house.

Exercise | Q 30 | Page 22

From the top of a 60m high building the angles of depression of the top and bottom of a lamp post are 30° and 60° respectively. Find the distance on the ground between the building and the lamp post and the difference in their heights.

Exercise | Q 31 | Page 22

From the top of a light house 96m high, the angles of depression of two ships in the river and at the same level as the base of the light house and on the same side of it, are α and β. If tan α = 1/4 and tan β = 1/7, find the distance between the ships.

Exercise | Q 32 | Page 22

The angle of elevation of a tower from a point 200 m from its base is θ, when tan θ = 2/5. The angle of elevation of this tower from a point 120m from its base is Φ. Calculate the height of tower and the value of Φ.

Exercise | Q 33 | Page 22

From a point 10 m above the ground , the angle of elevation of the top of a tower is α and the angle of depression is β . If tan α = 5/2 and tan β = 1/4 , calculate the height of the tower to the nearest metre .

Exercise | Q 34 | Page 22

A man on the deck of a ship is 10 m above the water level. He observes that the angle of elevation of the top of a diff is 45° and the angle of depression of the base is 30°. Find the distance of the diff from the ship and the height of the cliff.

Exercise | Q 35 | Page 22

Of the two trees are on either side of a river, one of them is 50m high. From the top of this tree the angles of depression of the top and the foot of the other tree are 30° and 60° respectively. Find the width of the river and the height of the other tree.

Exercise | Q 36 | Page 22

The length of the shadow of a statue increases by 8m, when the latitude of the sun changes from 45° to 30°. Calculate the height of the tower.

Exercise | Q 37 | Page 22

The angle of elevation of a tower from a point in line with its base is 45^circ . On moving 20m towards the tower , the angle of elevation changes to 60^circ . Find the height of the tower.

Exercise | Q 38 | Page 22

A man on the top of a tower observes that a car is moving directly at a uniform speed towards it. If it takes 720 seconds for the angle of depression to change from 30° to 45°, how soon will the car reach the observation tower?

Exercise | Q 39 | Page 22

The horizontal distance between towers is 140 m. The angle of elevation of the top of the first tower when seen from the top of the second tower is 30°. If the height of the second tower is 60m, find the height of the first tower.

Exercise | Q 40 | Page 22

An aeroplane when flying at a height of 4km from the ground passes vertically above another aeroplane at an instant when the angles of the elevation of the two planes from the same point on the ground are 60° and 45° respectively. Find the vertical distance between the aeroplanes at that instant.

Exercise | Q 41 | Page 22

A parachutist is descending vertically and makes angles of elevation of 45° and 60° from two observing points 100 m apart to his right. Find the height from which he falls and the distance of the point where he falls on the ground from the nearest observation pcint.

Exercise | Q 42 | Page 22

The angle of elevation of a stationary cloud from a point 25m above a lake is 30° and the angle of depression of its reflection in the lake is 60°. What is the height of the cloud above the lake-level?

Exercise | Q 43 | Page 22

The angle of elevation of a cloud from a point 60m above a lake is 30° and the angle of depression of its reflection in the lake is 60°. Find the height of the cloud.

Exercise | Q 44 | Page 22

A man in a boat rowing away from a lighthouse 180 m high takes 2 minutes to change the angle of elevation of the top of the lighthouse from 60° and 30°. Find the speed of the boat.

Exercise | Q 45 | Page 22

The angle of depression of a boat moving towards a diff is 30°. Three minutes later the angle of depression of the boat is 60°. Assuming that the boat is sailing at a uniform speed, determine the time it will take to reach the shore. Also, find the speed of the boat in m/second if the cliff is 450m high.

Exercise | Q 46 | Page 22

A man standing on a cliff observes a ship at an angle of depression of the ship is 30°, approaching the shore just beneath him. Three minutes later, the angle of depression of the ship is 60°. How soon will it reach the shore?

Exercise | Q 47 | Page 22

A man on the top of a tower observes a truck at an angle of depression ∝ where ∝ = 1/sqrt(5) and sees that it is moving towards the base of the tower.  Ten minutes later, the angle of depression of the truck is found to β = sqrt(5). Assuming that the truck moves at a uniform speed, determine how much more ti me it will take to each the base of the tower?

Exercise | Q 48 | Page 22

The angle of elevation of an aeroplane from a point on the ground is 45°. After 15 seconds, the angle of elevation changes to 30°. If the aeroplane is flying at a height of 3000 m, find the speed of the aeroplane.

Exercise | Q 49 | Page 22

The angle of elevation of the top Q of a vertical tower PQ from a point X on the ground is 60°. At a point Y, 40m vertically above X, the angle of elevation is 45°. Find the height of the tower PQ and the distance XQ.

Exercise | Q 50 | Page 22

If the angle of elevation of a cloud from a point h m above a lake is α, and the angle of depression of its reflection in the lake be β, prove that distance of the cloud from the point of observation is ("2h"secα)/(tanα - tanβ).

Exercise | Q 51 | Page 22

From an aeroplane vertically above a straight horizontal road, the angles of depression of two consecutive milestone on opposite sides of the aeroplane are observed to be α, and β. Show that the height in miles of aeroplane above the road is (tanα  tanβ)/(tanα + tanβ).

Exercise | Q 52 | Page 22

A ladder rests against a wall at an angle a, to the horizontal. Its foot is pulled away from the wall through a distance 'a', so that it slides a distance 'b' down the wall making an angle β with the horizontal. Show that "a"/"b" = (cosα - cosβ)/(sinβ - sinα).

Exercise | Q 53 | Page 22

From the top of a lighthouse, the angles of depression of two ships on the opposite sides of it are observed to be α, and β. If the height of the light house is 'h' m and the line joining the ships passes through the foot of the light house, show that the distance between the ship is ("h"(tan α + tan β))/(tanα  tanβ)m.

Exercise

## Frank solutions for Class 10 Mathematics chapter 22 - Heights and Distances

Frank solutions for Class 10 Maths chapter 22 (Heights and Distances) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CISCE Frank Class 10 Mathematics Part 2 solutions in a manner that help students grasp basic concepts better and faster.

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Concepts covered in Class 10 Mathematics chapter 22 Heights and Distances are Trigonometric Ratios of Complementary Angles, Trigonometric Identities, Heights and Distances - Solving 2-D Problems Involving Angles of Elevation and Depression Using Trigonometric Tables, Trigonometry Problems and Solutions.

Using Frank Class 10 solutions Heights and Distances exercise by students are an easy way to prepare for the exams, as they involve solutions arranged chapter-wise also page wise. The questions involved in Frank Solutions are important questions that can be asked in the final exam. Maximum students of CISCE Class 10 prefer Frank Textbook Solutions to score more in exam.

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