Answer:
20 degrees
Explanation:
Applying the second law of reflection,
Second Law of reflection: The law of refelection states that the incident angle, reflected angle.
Mathematically, it can be expressed as
i = r...................... Equation 1
From the question, we were told that the light strik the plane at an angle of 20 degrees to the normal.
Therefore,
i = 20 degrees.
If i = 20 degrees,
then,
r = 20 degrees.
