# Some Applications of Trigonometry – Class X – Part 1 | Exercise 9.1 Q1-3 Solved

### Watch the first video session on “Some Applications of Trigonometry” for Class Xth – concepts and solved questions

Some Applications of Trigonometry – NCERT Class X – Part 1

1. Astronomers used Trigonometry to calculate distances from the Earth to the other planets and starts.

2. It is also used to construct in geography to construct maps and in navigation.

3. Line connecting the observer’s eye to the position of the object being viewed is called line of sight.

4.Horizontal level is the line that we get when we look absolutely straight (neither up or down).

5. Angle formed between line of site and horizontal level is called the angle of elevation.

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NCERT Exercise 9.1 Q1 – 3 Solved

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 video for the figure).

2. A tree breaks due to storm and the broken part bends so that the top of the tree touches the ground making an angle 30° with it. The distance between the foot of the tree to the point where the top touches the ground is 8 m. Find the height of the tree.

3. A contractor plans to install two slides for the children to play in a park. For the children below the age of 5 years, she prefers to have a slide whose top is at a height of 1.5 m, and
is inclined at an angle of 30° to the ground, whereas for elder children, she wants to have a steep slide at a height of 3m, and inclined at an angle of 60° to the ground. What should be the length of the slide in each case?

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