Under what condition in an arrangement of two plane mirrors, incident ray and reflected ray will always be parallel to each other, whatever may be angle of incidence. Show the same with the help of diagram.

Explanation

To determine the condition under which the incident ray and the reflected ray will always be parallel to each other when using two plane mirrors, we can analyze the arrangement and angles involved. The key condition is that the two mirrors must be positioned at a right angle (90 degrees) to each other. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have two plane mirrors, let's call them Mirror 1 and Mirror 2.
- These mirrors are arranged such that they meet at a right angle (90 degrees).

...