What are the different types of polygons and triangles?

Polygons are close plane shapes formed by straight sides. Poly means many; so a polygon is a closed figure with many straight sides. Simplest polygon is a triangle and it has 3 sides. 

Types of polygons

Three-sided polygon: Triangle

Four-sided polygon: Quadrilateral

Five-sided Polygon: Pentagon

Six-sided polygon: Hexagon

Seven-sided polygon: Heptagon

Eight-sided polygon: Octagon

Nine-sided polygon: Nonagon

Ten-sided polygon: Decagon and so on

Types of triangles:

Triangles based on sides

Equilateral triangle

Isosceles triangle

Scalene triangle

Triangles based on angles

Acute triangle

Right triangle

Obtuse triangle