A man sitting at a height of 20m on a tall tree on a small island in the middle of a river observes two poles directly opposite to each other on the two banks of the river and in line with the foot of tree. If the angles of depression of the feet of the poles from a point at which the man is sitting on the tree on either side of the river are `60^0a n d30^0` respectively. Find the width of the river.

Explanation

To solve the problem, we will use trigonometry to find the width of the river based on the given angles of depression and the height of the tree.

### Step-by-Step Solution:

1. **Understand the Setup**:
- A man is sitting on top of a tree that is 20 meters high.
- There are two poles on opposite banks of the river, and the angles of depression to the feet of the poles are given as 60° and 30°.

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