30

150

Because the incident angle is equal to the reflection angle, it is equal to 120 divided by 2 is equal to 60.

The angle between light and mirror is 90 degrees-the angle of incident (reflected) light, so it is equal to 90-60 and 30.

When the reflection angle increases15, the incident angle also increases15, and the included angle between incident light and reflected light is120+15+15 =150.

I hope it will help you (* _ _ *)