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Mathematics · Some Applications of Trigonometry · NCERT Examples

Example 1

A complete, independently verified solution for NCERT Example 1.

Mathematics · Chapter 9 · NCERT Examples

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Verified NCERT questions and solutionsSolutions are checked independently and follow the supplied NCERT chapter edition.

NCERT Example

Example 1

angle of elevation · tower height

A tower stands vertically on the ground. From a point 15 m away from the foot of the tower, the angle of elevation of its top is 60°. Find the height of the tower.

Tower AB, point C on the ground 15 metres from its foot B, and a 60 degree angle of elevation to A.
Figure 9-4 from the supplied NCERT chapter.

Solution

Board-exam working:

Let AB be the height of the tower and BC = 15 m.

tan⁡60∘=ABBC\tan 60^\circ=\frac{AB}{BC}
3=AB15\sqrt3=\frac{AB}{15}
AB=153 mAB=15\sqrt3\text{ m}

Final answer

The height of the tower is 15√3 m.