Ex 9.1, 1 - A circus artist is climbing a 20 m long rope - Ex 9.1

  1. Chapter 9 Class 10 Some Applications of Trigonometry
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Ex 9.1, 1 A circus artist is climbing a 20 m long rope, which is tightly stretched and tied from the top of a vertical pole to the ground. Find the height of the pole, if the angle made by the rope with the ground level is 30° Let, the height of pole be AB. Assuming that rope is tied at point C. It is given that, Length of rope = 20 m Hence, AC = 20m Also, angle made by rope with the ground level = 30° Hence, ∠ACB=30° We need to find height of pole i.e. AB Since the pole is vertical, ∠ ABC = 90° In right triangle ABC sin C = (𝑆𝑖𝑑𝑒 𝑜𝑝𝑝𝑜𝑠𝑖𝑡𝑒 𝑡𝑜 𝑎𝑛𝑔𝑙𝑒" " 𝐶" " )/𝐻𝑦𝑝𝑜𝑡𝑒𝑛𝑢𝑠𝑒 sin 30°= 𝐴𝐵/𝐴𝐶 (1 )/2 = 𝐴𝐵/20 1/2×20 = AB 10 = AB AB = 10 ∴ Height of pole = AB = 10 metre.

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  • Parminder Kaur's image
    Parminder Kaur
    May 5, 2018, 4:22 p.m.
    Why we take sin here how do we know 

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  • Akshay Soni's image
    In angle ABC right angle at B,AB = 24 cm,BC 7 cm Determine.       
    1.sin A , cos A.  2. Sin C  , cos C

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  • muthukumaran arulanandam's image
    muthukumaran arulanandam
    Jan. 10, 2018, 7:38 p.m.
    The angle of elevation of the top of a building from the foot of the tower is 30° and the angle of elevation of the top of the tower from the foot of the building is 45°. If the tower is 30m high find the height of the building.



    Please help me out in this sum



    With step please
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