The diagram models specular reflection from a plane surface. Reflection preserves the tangential component of the incident direction and reverses the normal component, so incidence and reflection angles match. Rotating the normal changes both sides of that angular construction. Surface roughness, finite beam width and absorption are omitted from the ray sketch.
Light, sound and electricity · Discover & try
How can a mirror redirect light?
Reading level 5 of 5 · AdvancedChange
Word help
normal
A line perpendicular to a surface.
reflection
Light returning from a surface.
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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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