[h3]The Normal[/h3]
[ul]
[li]A normal is an imaginary line drawn perpendicular to a surface. (90[degree] to a surface).[/li]
[li]It is very ease to draw in 2D.[/li]
[li]It is the line directly in between the incident and the reflected waves.[/li]
[/ul]
[h3]The laws of Reflection[/h3]
[b]1)[/b] The angle of incidence is equal to the angle of reflection
[img src='https://res.cloudinary.com/deylrqt2d/image/upload/v1487947450/angle_incidence_is_angle_reflection_w0hnbd.svg' style='width:100vw;']
[ul]
[li]Angles are always measured between the ray and the normal.[/li]
[li]The [b]N[/b], represent the [b]Normal[/b].[/li]
[li][b]i[degree][/b] represents the [b]incidence ray[/b], the ray coming towards the plane.[/li]
[li][b]r[degree][/b] represent the [b]reflected ray[/b], the ray reflected from the plane.[/li]
[/ul]
[code]
[b]i[degree] is equal to r[degree][/b].
[/code]
[b]2)[/b]The incident ray, the reflected ray and the normal, all lie on the same plane. (Flat surface).
[hr]
[h3]A periscope[/h3]
[img src='https://res.cloudinary.com/deylrqt2d/image/upload/v1487951335/periscope_rg8skd.svg' style='width:100vw;']
Only through the reflected rays do you see an image.