Polygons

Flat Shape, Straight Edges

The straight lines of a polygon are called edges or sides

A Polygon is a 2 dimensional flat shape that is made up of straight lines.
A flat (closed) shape with 3 or more straight lines.

They are made up of straight lines which are connected together
All polygon shapes are closed.

Regular

All the sides are the same length / have equal length
All the angles are the same size

Irregular

Not all the sides are the same length
Not all the angles are the same size

Convex

No angles are pointing inwards
No internal angle is greater than 180 degrees

Concave

At least one internal angle is greater than 180 degrees

Complex

At least one of the lines intersect or cross