Answer
P = 20
s = 2.5
A = 30.177669529664
Interior Angle sum = 1080°
Diagonals = 20
1 vertex Diagonals = 5
Triangles = 6
Sides (Edges) = 8
Faces = 1
Vertices = 8
s = 2.5
A = 30.177669529664
Interior Angle sum = 1080°
Diagonals = 20
1 vertex Diagonals = 5
Triangles = 6
Sides (Edges) = 8
Faces = 1
Vertices = 8
↓Steps Explained:↓
The Perimeter of an octagon is 20
Calculate side, area
Calculate side:
| s = | P |
| 8 |
| s = | 20 |
| 8 |
s = 2.5
Calculate Area:
A = 2(1+√2)side2
A = 2(2.4142135623731)2.52
A = 4.8284271247462(6.25)
A = 30.177669529664
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
P = 20s = 2.5
A = 30.177669529664
Interior Angle sum = 1080°
Diagonals = 20
1 vertex Diagonals = 5
Triangles = 6
Sides (Edges) = 8
Faces = 1
Vertices = 8
Related Calculators: Polygons | Heptagon | Decagon