The normal line is a line at a right angle (90 degrees) to the surface of an object

To draw a normal line to the mirror, you must draw a line at 90 degrees to the surface of the mirror.

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Lesson Video: Normal Reaction Force on a Sloping Surface

Right Angle - Definition, Properties, Shape, Examples

What is flux in physics?

Right angle - Math Steps, Examples & Questions

Normal line - Tilted flat mirrors

labeled planes in the image with the plane name in

Aligning Object to Surface using CFrame:fromMatrix() - Community Tutorials - Developer Forum

A ray of light falls on an object perpendicular to it's surface then what would be the angle of incidence and angle of reflection? - Quora

Lesson Explainer: Critical Angle for Total Internal Reflection

Angle of Reflection Definition, Types & Formula - Lesson