Question 13

What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?

Answer

angle

∠i + ∠r = 90◦

But, by the first law of reflection;

∠i = ∠r

∠i + ∠r = 90◦

∠i + ∠i = 90◦

2∠i = 90◦

∠i = 90◦ = 45◦ 2

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