Apothem of a regular polygon

How to find the area of an irregular polygon by breaking it down into triangles

A method for finding the area of any polygon - regular, irregular, convex, concave if you know the coordinates of the vertices.

Definition of the center of a polygon

Definition of the central angle of a polygon

The circumcircle of a polygon is defined: the circle that passes through every vertex.

Definition and properties of a concave polygon

Four different ways to test if polygons are congruent.

Polygons are congruent when all corresponding sides and interior angles are congruent.

Definition and properties of a convex polygon

Definition and properties of a decagon

Definition and properties of a dodecagon

Definition and properties of a heptagon

Definition and properties of a hexagon

The incircle of a regular polygon is defined along with its radius and formula for finding it.

A discussion and example of how the interior and exterior angles of a polygon are related, especially when the polygon is concave.

Definition an properties of an irregular polygon

Definition and properties of a nonagon (enneagon)

octagon

Definition of a pentagon

Formula and description of the perimeter of a polygon.

A calculator that will calculate the area of a polygon given the coordinates of its vertices

Polygon definition and properties

Definition of the diagonals of a polygon, including a formula to calculate the number of them in an n-gon

The exterior angles of a polygon and the method for calculating their values.

The interior angles of a polygon and the method for calculating their values.

The radius of a regular polygon and formula for finding it.

Formula for the area of a regular polygon

Definition of a regular (equiangular) polygon

The sides of a polygon are defined and two formulas for finding the side length for a regular polygon.

Definition and properties of similarity

Definition and properties of a tetragon

Definition of the triangles of a polygon, including a formula to calculate the number of them in an n-gon

Definition and properties of an undecagon