Reflection follows a simple rule: the angle of incidence equals the angle of reflection, measured from the normal. Both rays and the normal lie in one plane. A smooth mirror keeps an orderly reflected beam; a rough surface sends rays in many directions because its tiny surface patches face different ways.
Light, sound and electricity · Discover & try
How can a mirror redirect light?
Reading level 3 of 5 · IndependentChange
Word help
normal
A line perpendicular to a surface.
reflection
Light returning from a surface.
Watch · Try · Explain
See how it works
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One ideal plane mirror; ray directions are geometric and no laser is needed.
What to look for
- Angles use the perpendicular normal
- The incident ray remains fixed
- Turning the mirror redirects the reflected ray
Explain what you noticed
A ray meets a flat mirror at 25° from the normal. What is its reflected angle from the normal?
Keep this idea: Compare both ray angles with the normal.
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Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
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