Regular and Irregular Polygons

Irregular convex polygon

Sum of interior angles of an n-sided convex polygon:

i=1nαi=α1+α2+α3+  +αn=n-2·180°

Sum of exterior angles of an n-sided convex polygon:

i=1nαi'=α1'+α2'+α3'+  +αn'=360°

Number of diagonals of an n-sided convex polygon:

N=n·n-32

The size of an angle of an n-sided regular polygon:

α=n-2·180°n

The size of the central angle of an n-sided regular polygon:

β=360°n

Perimeter of a regular polygon with n sides:

K=n·a

The area of ​​a regular polygon with n sides, based on side and the circumference of the circle inscribed in the polygon:

T=12·n·a·r

Area of ​​a regular polygon with n sides, based on the circumference of the circle inscribed in the polygon and the central angle:

T=n·R2·sin β2

Area of ​​an n-sided regular polygon, based on side and central angle:

T=n·a2·ctg β24

Keywords: convex polygon, regular, irregular, number of diagonals, sum of interior angles, sum of exterior angles, area, perimeter