# Polygons

Posted in Terms Defined

Polygon: A simple closed curve made up of only line segments is called a polygon.

Classification of polygons:

 Number of Sides Classification 3 Triangle 4 Quadrilateral 5 Pentagon 6 Hexagon 7 Heptagon 8 Octagon 9 Nonagon 10 Decagon ... ... n n-gon

Diagonal: A diagonal is a line segment connecting two non-consecutive vertices of a polygon.

Convex polygons: Where all the interior angles are less than 180° and no part of its diagonals lie outside the polygon.

Concave polygons: Where at least one interior angle is more than 180° and some of the diagonals will lie outside the polygon.

Regular polygons: A regular polygon is both 'equiangular' and 'equilateral'. e.g. equilateral triangle.

Irregular polygons: Polygons which are not equiangular or equilateral are irregular polygons. e.g. right-angled triangle.

Angle sum property: Sum of all interior angles = $$(n - 2) \times 180°$$ where n --> number of interior angles.