l Decagon side = 20

Enter a value and then press the button of what measurement you entered

    

Answer
s = 20
P = 200
A = 3077.6835371753
Sides (Edges) = 10
Faces = 1
Vertices = 10

↓Steps Explained:↓



The Side of an decagon is 20

Calculate perimeter, area

Calculate Perimeter:

P = 10 x side

P = 10 x 20

P = 200

Calculate Area:

A = 5/2s2√5 + 2√5

A = 2.5(20)2(3.0776835371753)

A = 2.5(400)(3.0776835371753)

A = 3077.6835371753

Calculate Sum of the Interior Angles:

Interior Angle Sum = (sides - 2) x 180°

Interior Angle Sum = (10 - 2) x 180°

Interior Angle Sum = 8 x 180°

Interior Angle sum = 1440°

Calculate decagon diagonals

Diagonals  =  n(n - 3)
  2

Diagonals  =  10(10 - 3)
  2

Diagonals  =  10(7)
  2

Diagonals  =  70
  2

Diagonals = 35

Calculate diagonals from 1 vertex:

1 vertex Diagonals = n - 3

1 vertex Diagonals = 10 - 3

1 vertex Diagonals = 7

Calculate number of Δ from 1 vertex:

Triangles = N - 2

Triangles = 10 - 2

Triangles = 8

Other Properties:

Sides (Edges) = 10

Faces = 1

Vertices = 10

s = 20
P = 200
A = 3077.6835371753
Sides (Edges) = 10
Faces = 1
Vertices = 10

Related Calculators:  Polygons  |  Nonagon  |  Pentagons