CBSE Board Practice

CBSE Grade X - Some Applications of Trigonometry
Question 1
1.
From a point 180 m away from a vertical cliff, the angles of elevation of the top and the foot of a vertical pillar at the top of the cliff are 60° and 30° respectively. Find the height of the pillar.
  • 207.85 m
  • 183.85 m
  • 224.85 m
  • 191.85 m
  • 215.85 m
Question 2
2.
A man in a boat rowing away from a lighthouse 65 m high, takes 3 min to change the angle of elevation of the top of the lighthouse from 45° to 30°. Find the speed of the boat.
  • 1.26 m/sec
  • 7.26 m/sec
  • 0.26 m/sec
  • 8.26 m/sec
  • 2.26 m/sec
Question 3
3.
    • From the top of a 17 m high building , the angle of elevation of the top of a cable tower is 44°54' and the angle of depression of its foot is 36°5'. Find the height of the cable tower.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      44
      0.9657
      0.9691
      0.9725
      0.9759
      0.9793
      0.9827
      0.9861
      0.9896
      0.9930
      0.9965
      6
      11
      17
      23
      28
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      36
      0.7265
      0.7292
      0.7319
      0.7346
      0.7373
      0.7400
      0.7427
      0.7454
      0.7481
      0.7508
      5
      9
      14
      18
      23
  • 40.24 m
  • 37.24 m
  • 45.24 m
  • 43.24 m
  • 35.24 m
Question 4
4.
A man on the top of a vertical observation tower observes a car moving at a uniform speed coming directly towards him. If it takes 19 min for the angle of depression to change from 45° to 60°, how soon after this, will the car reach the observation tower?
  • 24 min 56 sec
  • 23 min 54 sec
  • 27 min 60 sec
  • 26 min 58 sec
  • 25 min 57 sec
Question 5
5.
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 .
  • 18.86 m
  • 26.86 m
  • 16.86 m
  • 21.86 m
  • 24.86 m
Question 6
6.
From a point 80 m away from a vertical cliff, the angles of elevation of the top and the foot of a vertical pillar at the top of the cliff are 60° and 45° respectively. Find the height of the cliff.
  • 75.00 m
  • 77.00 m
  • 85.00 m
  • 80.00 m
  • 83.00 m
Question 7
7.
    • A
    • chimney
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • chimney
    • is found to be
    • 60°
    • .
    • If the distance between the point and the top of the
    • chimney
    • is
    • 150 m
    • ,
    • find the height of the
    • chimney
    • .
  • 225

    2



    2
    m
  • 75
    m
  • 75



    3
    m
  • 225
    m
  • 75



    18
    m
Question 8
8.
    • 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 34°41'. If the height of the building is 11 m, find the distance between the observation point and the foot of the building.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      34
      0.6745
      0.6771
      0.6796
      0.6822
      0.6847
      0.6873
      0.6899
      0.6924
      0.6930
      0.6976
      4
      9
      13
      17
      22
    • From Table of Natural Sines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      34
      0.5592
      0.5606
      0.5621
      0.5635
      0.5650
      0.5664
      0.5678
      0.5693
      0.5707
      0.5721
      2
      5
      7
      9
      12
  • 10.89 m
  • 20.89 m
  • 12.89 m
  • 15.89 m
  • 18.89 m
Question 9
9.
    • The upper part of a tree is broken into two parts without being detatched. It makes an angle of 33°24' with the ground. The top of the tree touches the ground at a distance of 190 m from the foot of the tree . Find the height of the tree before it was broken.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      33
      0.6494
      0.6519
      0.6544
      0.6569
      0.6594
      0.6619
      0.6644
      0.6669
      0.6694
      0.6720
      4
      8
      13
      17
      21
    • From Table of Natural Cosines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      33
      0.8387
      0.8377
      0.8368
      0.8358
      0.8348
      0.8339
      0.8329
      0.8320
      0.8310
      0.8300
      2
      3
      5
      7
      8
  • 370.89 m
  • 345.89 m
  • 336.89 m
  • 368.89 m
  • 352.89 m
Question 10
10.
A boy standing on a vertical cliff in a jungle observes two rest houses in line with him on opposite sides deep in the jungle below. If their angles of depression are 45° and 60° and the distance between them is 125 m , find the height of the cliff.
  • 82.25 m
  • 84.25 m
  • 79.25 m
  • 76.25 m
  • 74.25 m