EduSahara™ Assignment
Name : Heights and Distances
Chapter : Some Applications of Trigonometry
Grade : CBSE Grade X
License : Non Commercial Use
Question 1
1.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • 30°
    • .
    • If the height of the
    • tower
    • is
    • 80 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • (i)
    160
    m
  • (ii)
    162
    m
  • (iii)
    161
    m
  • (iv)
    159
    m
  • (v)
    157
    m
Question 2
2.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • 30°
    • .
    • If the height of the
    • tower
    • is
    • 110 m
    • ,
    • find the distance between
    • the observation point and the foot of the
    • tower
    • .
  • (i)
    110



    3
    m
  • (ii)
    165



    2
    m
  • (iii)
    110



    18
    m
  • (iv)
    110
    m
  • (v)
    330
    m
Question 3
3.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • 30°
    • .
    • If the distance between the point and the foot of the
    • tower
    • is
    • 20 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • (i)
    40

    3



    18
    m
  • (ii)
    20



    2
    m
  • (iii)
    40

    3



    3
    m
  • (iv)
    40
    m
  • (v)
    40

    3
    m
Question 4
4.
    • A
    • radio tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • radio tower
    • is found to be
    • 60°
    • .
    • If the distance between the point and the foot of the
    • radio tower
    • is
    • 70 m
    • ,
    • find the height of the
    • radio tower
    • .
  • (i)
    210
    m
  • (ii)
    105



    2
    m
  • (iii)
    70



    18
    m
  • (iv)
    70
    m
  • (v)
    70



    3
    m
Question 5
5.
    • A
    • building
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • building
    • is found to be
    • 45°
    • .
    • If the distance between the point and the top of the
    • building
    • is
    • 100 m
    • ,
    • find the height of the
    • building
    • .
  • (i)
    100
    m
  • (ii)
    25



    12
    m
  • (iii)
    50
    m
  • (iv)
    100



    3
    m
  • (v)
    50



    2
    m
Question 6
6.
    • A
    • radio tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • radio tower
    • is found to be
    • 60°
    • .
    • If the distance between the point and the top of the
    • radio tower
    • is
    • 10 m
    • ,
    • find the distance between
    • the observation point and the foot of the
    • radio tower
    • .
  • (i)
    6
    m
  • (ii)
    4
    m
  • (iii)
    3
    m
  • (iv)
    8
    m
  • (v)
    5
    m
Question 7
7.
Two boys are on opposite sides of a tower of 40 m height. They measure the angle of elevation of the top of the tower as 60° and 30° respectively. Find the distance between the two boys.
  • (i)
    160

    3
    m
  • (ii)
    160

    3



    3
    m
  • (iii)
    160

    3



    18
    m
  • (iv)
    80



    2
    m
  • (v)
    160
    m
Question 8
8.
A person, walking 20 m from a point toward a flagpost , observes that its angle of elevation changes from 45° to 60°. Find the height of the flagpost .
  • (i)
    (
    30
    +
    10



    3
    )
    m
  • (ii)
    600
    m
  • (iii)
    (
    2
    +



    3
    )
    m
  • (iv)
    (
    15



    6
    +
    15



    2
    )
    m
  • (v)
    (
    30



    6
    +
    10



    18
    )
    m
Question 9
9.
A flagstaff stands on the top of a building at a distance of 10 m away from the foot of building . The angle of elevation of the top of the flagstaff is 60° and the angle of elevation of the top of the building is 45°. Find the height of the flagstaff .
  • (i)
    (
    15



    2
    5



    6
    )
    m
  • (ii)
    (
    2



    3
    )
    m
  • (iii)
    200
    m
  • (iv)
    (
    10



    3
    10
    )
    m
  • (v)
    (
    10



    18
    10



    6
    )
    m
Question 10
10.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • sin
      (-1)
       
      (
      2

      5
      )
    • .
    • If the height of the
    • tower
    • is
    • 30 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • (i)
    75.00 m
  • (ii)
    78.00 m
  • (iii)
    72.00 m
  • (iv)
    80.00 m
  • (v)
    70.00 m
Question 11
11.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • cos
      (-1)
       
      (
      6

      7
      )
    • .
    • If the distance between the point and the top of the
    • tower
    • is
    • 130 m
    • ,
    • find the distance between
    • the observation point and the foot of the
    • tower
    • .
  • (i)
    87.43 m
  • (ii)
    129.43 m
  • (iii)
    124.43 m
  • (iv)
    104.43 m
  • (v)
    111.43 m
Question 12
12.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • tan
      (-1)
       
      (
      4

      9
      )
    • .
    • If the distance between the point and the foot of the
    • tower
    • is
    • 20 m
    • ,
    • find the height of the
    • tower
    • .
  • (i)
    6.89 m
  • (ii)
    7.89 m
  • (iii)
    9.89 m
  • (iv)
    10.89 m
  • (v)
    8.89 m
Question 13
13.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • cosec
      (-1)
       
      (
      5

      3
      )
    • .
    • If the distance between the point and the top of the
    • tower
    • is
    • 20 m
    • ,
    • find the height of the
    • tower
    • .
  • (i)
    12.00 m
  • (ii)
    9.00 m
  • (iii)
    15.00 m
  • (iv)
    7.00 m
  • (v)
    17.00 m
Question 14
14.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • sec
      (-1)
       
      (
      10

      7
      )
    • .
    • If the distance between the point and the foot of the
    • tower
    • is
    • 50 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • (i)
    66.43 m
  • (ii)
    76.43 m
  • (iii)
    74.43 m
  • (iv)
    71.43 m
  • (v)
    68.43 m
Question 15
15.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • cot
      (-1)
       
      (
      1

      9
      )
    • .
    • If the distance between the point and the foot of the
    • tower
    • is
    • 160 m
    • ,
    • find the height of the
    • tower
    • .
  • (i)
    1290.00 m
  • (ii)
    1560.00 m
  • (iii)
    1320.00 m
  • (iv)
    1440.00 m
  • (v)
    1570.00 m
Question 16
16.
    • A
    • tower
    • stands vertically on the ground.
    • The distance between the observation point and its foot
    • tower
    • is
    • 10



      3
      m
    • .
    • The distance between the observation point and its top
    • is
    • 20
      m
    • .
    • Find the angle of elevation.
  • (i)
    30°
  • (ii)
    90°
  • (iii)
    75°
  • (iv)
    60°
  • (v)
    45°
Question 17
17.
The upper part of a tree is broken into two parts without being detatched. It makes an angle of 45° with the ground. The top of the tree touches the ground at a distance of 10 m from the foot of the tree . Find the height of the tree before it was broken.
  • (i)
    29.14 m
  • (ii)
    24.14 m
  • (iii)
    27.14 m
  • (iv)
    19.14 m
  • (v)
    21.14 m
Question 18
18.
There are two temples one on each bank of a river, just opposite to each other. One of the temples is 190 m high. As observed from the top of this temple, the angles of depression of the top and foot of the other temple are 45° and 60° respectively. Find the width of the river .
  • (i)
    125.69 m
  • (ii)
    112.69 m
  • (iii)
    94.69 m
  • (iv)
    109.69 m
  • (v)
    97.69 m
Question 19
19.
There are two temples one on each bank of a river, just opposite to each other. One of the temples is 160 m high. As observed from the top of this temple, the angles of depression of the top and foot of the other temple are 30° and 60° respectively. Find the height of the other temple.
  • (i)
    114.66 m
  • (ii)
    106.66 m
  • (iii)
    90.66 m
  • (iv)
    118.66 m
  • (v)
    103.66 m
Question 20
20.
An observer 1.8 m tall, is 130 m away from a tower . The angle of elevation of the top of the tower from her eyes is 45°. Find the height of the tower .
  • (i)
    133.80 m
  • (ii)
    131.80 m
  • (iii)
    149.80 m
  • (iv)
    115.80 m
  • (v)
    116.80 m
Question 21
21.
Two poles of equal height are standing opposite to each other on either side of a road which is 45 m wide. From a point between them on the road, the angles of elevation of the top of the poles are 30° and 60° respectively. Find the height of each pole and the distances of the point from the two poles .
  • (i)
      • height =
      • 17.49 m
      • , distances away =
      • 9.25 m
      • ,
      • 31.75 m
  • (ii)
      • height =
      • 21.49 m
      • , distances away =
      • 13.25 m
      • ,
      • 35.75 m
  • (iii)
      • height =
      • 19.49 m
      • , distances away =
      • 11.25 m
      • ,
      • 33.75 m
  • (iv)
      • height =
      • 18.49 m
      • , distances away =
      • 10.25 m
      • ,
      • 32.75 m
  • (v)
      • height =
      • 20.49 m
      • , distances away =
      • 12.25 m
      • ,
      • 34.75 m
Question 22
22.
From the top of a light house which is 90 m high from the sea level, the angles of depression of two ships are 45° and 30°. If one ship is exactly behind the other on the same side of the light house , find the distance between the two ships.
  • (i)
    68.87 m
  • (ii)
    70.87 m
  • (iii)
    65.87 m
  • (iv)
    62.87 m
  • (v)
    60.87 m
Question 23
23.
From the top of a 12 m high building , the angle of elevation of the top of a cable tower is 45° and the angle of depression of its foot is 30°. Find the height of the cable tower.
  • (i)
    37.78 m
  • (ii)
    35.78 m
  • (iii)
    27.78 m
  • (iv)
    29.78 m
  • (v)
    32.78 m
Question 24
24.
The angle of elevation of the top of a building from the foot of a tower is 60°. The angle of elevation of the top of the tower from the foot of the building is 45°. If the height of the tower is 100 m, find the height of the building .
  • (i)
    160.21 m
  • (ii)
    168.21 m
  • (iii)
    173.21 m
  • (iv)
    197.21 m
  • (v)
    189.21 m
Question 25
25.
A flag is hoisted at the top of a building . From a point on the ground, the angle of elevation of the top of the flag staff is 60° and the angle of elevation of the top of the building is 45°. If the height of the building is 15 m, find the height of the flag staff .
  • (i)
    10.98 m
  • (ii)
    5.98 m
  • (iii)
    15.98 m
  • (iv)
    13.98 m
  • (v)
    7.98 m
Question 26
26.
A flag is hoisted at the top of a building . From a point on the ground, the angle of elevation of the top of the flag staff is 45° and the angle of elevation of the top of the building is 30°. If the height of the flag staff is 16 m, find the height of the building .
  • (i)
    18.86 m
  • (ii)
    16.86 m
  • (iii)
    26.86 m
  • (iv)
    24.86 m
  • (v)
    21.86 m
    Assignment Key

  •  1) (i)
  •  2) (i)
  •  3) (iii)
  •  4) (v)
  •  5) (v)
  •  6) (v)
  •  7) (ii)
  •  8) (i)
  •  9) (iv)
  •  10) (i)
  •  11) (v)
  •  12) (v)
  •  13) (i)
  •  14) (iv)
  •  15) (iv)
  •  16) (i)
  •  17) (ii)
  •  18) (iv)
  •  19) (ii)
  •  20) (ii)
  •  21) (iii)
  •  22) (iii)
  •  23) (v)
  •  24) (iii)
  •  25) (i)
  •  26) (v)