What are Polygons ?
- Polygons are plane figures with at least three straight sides and angles, and typically five or more.
- For example - Triangles, quadrilaterals, pentagons, hexagons etc. are all polygons
Different Types of Polygons based on number of Sides.
Triangle
- It is a 3-sided polygon
- It has 3 sides , 3 vertices and 3 angles.
- It has no diagonals.
- Sum of all interior angles of a triangle = 180°
- Equilateral triangle has all 3 sided of equal length and each angle of measure 60°
Quadrilateral
- It is a 4-sided polygon
- It has 4 sides , 4 vertices and 4 angles.
- It has 2 diagonals.
- It is made up of 2 triangles.
- Sum of all interior angles of a quadrilateral = 360°
- Square is a 4-sided quadrilateral with all 4 sides of equal length and each angle of measure 90°
Pentagon
- It is a 5-sided polygon
- It has 5 sides , 5 vertices and 5 angles.
- It has 5 diagonals.
- It is made up of 3 triangles.
- Sum of all interior angles of a pentagon = 540°.
- Each angle of Regular Pentagon has of measure 108°
Hexagon
- It is a 6-sided polygon
- It has 6 sides , 6 vertices and 6 angles.
- It has 9 diagonals.
- It is made up of 4 triangles.
- Sum of all interior angles of a pentagon = 720°.
- Each angle of Regular Pentagon has of measure 120°
Heptagon/Septagon
- It is a 7 sided polygon
- It has 7 sides , 7 vertices and 7angles.
- It has 14 diagonals.
- It is made up of 5 triangles.
- Sum of all interior angles of a pentagon = 900°.
- Each angle of Regular Pentagon has of measure 128.571429°
Octagon
- It is a 8-sided polygon
- It has 8 sides , 8 vertices and 8 angles.
- It has 20 diagonals.
- It is made up of 6 triangles.
- Sum of all interior angles of a pentagon = 1080°.
- Each angle of Regular Pentagon has of measure 135°
Nonagon
- It is a 9-sided polygon
- It has 9 sides , 9 vertices and 9 angles.
- It has 27 diagonals.
- It is made up of 7 triangles.
- Sum of all interior angles of a pentagon = 1260°.
- Each angle of Regular Pentagon has of measure 140°
Decagon
- It is a 10 -sided polygon
- It has 10 sides , 10 vertices and 10 angles.
- It has 35 diagonals.
- It is made up of 8 triangles.
- Sum of all interior angles of a pentagon = 1440°.
- Each angle of Regular Pentagon has of measure 144°
Note :-
A polygon with n sides will have
- n angles
- n vertices
- ( n- 2) triangles in figure
- n(n-3)/2 Diagonals