Two plans mirrors are inclined to each other at some angle .A ray of light incident at `30^(@)`on one,after reflection form the other retraces its path .The angles between the mirrors is:
`30^(@) (2) 45^(@) (3) 60^(@) (4) 90^(@)`

Explanation

To solve the problem, we need to find the angle between two plane mirrors when a ray of light incident at \(30^\circ\) on one mirror retraces its path after reflecting from the other mirror.

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have two plane mirrors, let's call them Mirror M1 and Mirror M2.
- The angle between the two mirrors is denoted as \(\theta\).
- A ray of light strikes Mirror M1 at an angle of incidence of \(30^\circ\).
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