l Octagon side = 18

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

    

Answer
s = 18
P = 144
A = 1564.4103884178
Interior Angle sum = 1080°
Diagonals = 20
1 vertex Diagonals = 5
Triangles = 6
Sides (Edges) = 8
Faces = 1
Vertices = 8

↓Steps Explained:↓



The Side of an octagon is 18

Calculate perimeter, area

Calculate Perimeter:

P = 8 x side

P = 8 x 18

P = 144

Calculate Area:

A = 2(1+√2)side2

A = 2(2.4142135623731)182

A = 4.8284271247462(324)

A = 1564.4103884178

Calculate Sum of the Interior Angles:

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

Interior Angle Sum = (8 - 2) x 180°

Interior Angle Sum = 6 x 180°

Interior Angle sum = 1080°

Calculate polygon diagonals

Diagonals  =  n(n - 3)
  2

Diagonals  =  8(8 - 3)
  2

Diagonals  =  8(5)
  2

Diagonals  =  40
  2

Diagonals = 20

Calculate 1 vertex diagonals:

1 vertex Diagonals = n - 3

1 vertex Diagonals = 8 - 3

1 vertex Diagonals = 5

Calculate triangles from one vertex:

Triangles = N - 2

Triangles = 8 - 2

Triangles = 6

Other Properties:

Sides (Edges) = 8

Faces = 1

Vertices = 8

Final Answers

s = 18
P = 144
A = 1564.4103884178
Interior Angle sum = 1080°
Diagonals = 20
1 vertex Diagonals = 5
Triangles = 6
Sides (Edges) = 8
Faces = 1
Vertices = 8

Related Calculators:  Polygons  |  Heptagon  |  Decagon