CBSE Notes, Lectures

CBSE - Mathematics - Some Applications of Trigonometry

Some Applications of Trigonometry

NCERT Exercise Exercise 9.1

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° (see Fig. 9.11). 

Let AB be the vertical pole Ac be 20 m  long rope tied to point C.
In  right Δ ABC,
sin 30° = AB/AC
⇒ 1/2 = AB/20

⇒ AB = 20/2

⇒ AB = 10

The height of the pole is 10 m.

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