The angle of the outgoing ray is 100 degrees based upon the diagram.

The logic is as follows:

Say the incoming ray is incident on the first reflector at a 60 degree angle.

The outgoing ray from the first reflector is also at a 60 degree angle. This adds to the 50 degree angle provided to result in 110 degrees. Therefore the incoming ray on the second reflector is 70 degrees (180-110).

The outgoing ray off the second reflector is also at 70 degrees leaving the angle between the rays of 40 degrees (180-70-70).

You know the angle between the rays on the first reflector: 60 degrees (180-60-60).

So, the remaining angle is: 80 degrees. (180-40-60).

The angle that you are looking for is 100 degrees. (180-80).

The beautiful thing is that the angle remains at 100 degrees no matter what the angle is of the incoming ray (within limits; the incoming angle cannot equal or be less than 40 degrees).

Good luck.