Polygons
A figure is a polygon if it is a simple
Distinguish the following figures as a polygon or not:
Sides, vertices and diagonals
Polygon with six sides i.e. Hexagon
The line segments forming a polygon are called its Sides
Above polygon ABCDEF has the sides: AB, BC, CD, DE EF and FA.
The corners are usually named in order.
The meeting point of a pair of adjacent sides is called its vertex .
Sides EF and FA meet at F, so F is a vertex of the polygon ABCDEF. So, are points like A, B,C etc.
Any two sides with a common end point are called the adjacent sides of the polygon.
Are the sides AB and BC adjacent?
How about AF and DC?
The end points of the same side of a polygon are called the adjacent vertices. Vertices E and D are adjacent, whereas vertices A and D are not adjacent vertices.
Consider any pairs of vertices which are not adjacent and join them with a line segment.
The line segment joining two non-adjacent vertices in a polygon is called the diagonal of the polygon.
So, in the above figure- AD, BE, CF etc. are diagonals.
How many total diagonals does the polygon have?
If we try to join adjacent vertices with a line segment, what is the result? The line segment will be a