Advantage of measuring angles clockwise and counterclockwise from the normal

[Jodi]

Hi; I was wondering if someone could please help me with this question: "When you measure the law of reflection and the law of refraction, what is the advantage of making 2 measurements: one clockwise from the normal and one counterclockwise from the normal?" Could an advantage be that this is a good way of determining accuracy and seeing if you get the same results both ways? Could there be another advantage? Thank you for your help.

 

[quantumdude]

This question seems a bit odd, because if you are testing the law of reflection, you have to measure both angles. One is the angle of incidence and the other is the angle of reflection.