**Applications of Trigonometry Heights and Distances Chapter 9 Exercise 9.1 Question 11**

**11.** A TV tower stands vertically on a bank of a canal. From a point on the other bank directly opposite the tower, the angle of elevation of the top of the tower is . From another point 20 m away from this point on the line joining this point to the foot of the tower, the angle of elevation of the top of the tower is . Find the height of the tower and the width of the canal.

**Solution:**

In ,

m **(1)**

In

Putting equation** (1)**, we get

m

Using equation **(1)**, we have

m

Therefore, **Height of tower = AD =** m

**Width of Canal = DC = 10 m**