Two plane mirrors are inclined at an angle `theta` with each-other. A ray of light strikes one of them. Find its deviation after it has been reflected twice-one from each mirror.

Explanation

To solve the problem of finding the deviation of a ray of light after it has been reflected twice between two inclined plane mirrors, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have two plane mirrors inclined at an angle \( \theta \) to each other.
- A ray of light strikes one of the mirrors at an angle \( i_1 \).

...