**How to find the perimeter of an octagon: **In the previous article, we have discussed Python Program to Compute the Area and Perimeter of Heptagon

**Math Module :**

**How to find the perimeter of a octagon: **Python’s math module is a built-in module. By importing this module, we can perform mathematical computations.

Numerous mathematical operations like ceil( ),floor( ),factorial( ),mod( ),value of pi ,…..etc .can be computed with the help of math module.

**Octagon:**

**Perimeter of octagon formula: **An octagon is a polygon with eight sides. It has eight different angles.

Octagon = octa + gon, where octa is the number eight and gon is the number of sides.

In an octagon, there are 20 diagonals.

**Formula to calculate the area of an Octagon:**

*A = 2(1+⎷2)a²***Octagon’s**side length

**Formula to calculate the perimeter of a Oc**

**tagon****:****Oc**.

**tagon****Examples:**

**Example1:**

**Input:**

Given The Octagon's side length = 6

**Output:**

The Octagon's Area with given side length { 6 } = 173.82337649086284 The Octagon's Perimeter with the given side length { 6 } = 48

**Example2:**

**Input:**

Given The Octagon's side length = 12.5

**Output:**

The Octagon's Area with given side length { 12.5 } = 754.4417382415921 The Octagon's Perimeter with the given side length { 12.5 } = 100.0

## Program to Compute the Area and Perimeter of Octagon

**Perimeter of a octagon: **Below are the ways to Calculate the area and perimeter of a heptagon with the given Octagon’s side length:

### Method #1: Using Mathematical Formula (Static Input)

**Approach:**

- Import the math module using the import keyword.
- Give the Octagon’s side length as static input and store it in a variable.
- Calculate the area of the given Octagon using the above given mathematical formula and sqrt(), math.pow() functions.
- Store it in another variable.
- Calculate the perimeter of the given Octagon using the above given mathematical formula.
- Store it in another variable.
- Print the Octagon’s area with the given side length.
- Print the Octagon’s perimeter with the given side length.
- The Exit of the program.

**Below is the implementation:**

# Import the math module using the import keyword. import math # Give the Octagon's side length as static input and store it in a variable. side_len = 6 # Calculate the area of the given Octagon using the above given mathematical formula # and sqrt(), math.pow() functions. # Store it in another variable. octgn_area = (2*(1+math.sqrt(2))*math.pow(side_len, 2)) # Calculate the perimeter of the given Octagon using the above given mathematical formula. # Store it in another variable. octgn_perimetr = (8*side_len) # Print the Octagon's area with the given side length. print( "The Octagon's Area with given side length {", side_len, "} =", octgn_area) # Print the Octagon's perimeter with the given side length. print( "The Octagon's Perimeter with the given side length {", side_len, "} =", octgn_perimetr)

**Output:**

The Octagon's Area with given side length { 6 } = 173.82337649086284 The Octagon's Perimeter with the given side length { 6 } = 48

### Method #2: Using Mathematical Formula (User Input)

**Approach:**

- Import the math module using the import keyword.
- Give the Octagon’s side length as user input using float(input()) function and store it in a variable.
- Calculate the area of the given Octagon using the above given mathematical formula and sqrt(), math.pow() functions.
- Store it in another variable.
- Calculate the perimeter of the given Octagon using the above given mathematical formula.
- Store it in another variable.
- Print the Octagon’s area with the given side length.
- Print the Octagon’s perimeter with the given side length.
- The Exit of the program.

**Below is the implementation:**

# Import the math module using the import keyword. import math # Give the Octagon's side length as user input using float(input()) function and # store it in a variable. side_len = float(input("Enter some random number = ")) # Calculate the area of the given Octagon using the above given mathematical formula # and sqrt(), math.pow() functions. # Store it in another variable. octgn_area = (2*(1+math.sqrt(2))*math.pow(side_len, 2)) # Calculate the perimeter of the given Octagon using the above given mathematical formula. # Store it in another variable. octgn_perimetr = (8*side_len) # Print the Octagon's area with the given side length. print( "The Octagon's Area with given side length {", side_len, "} =", octgn_area) # Print the Octagon's perimeter with the given side length. print( "The Octagon's Perimeter with the given side length {", side_len, "} =", octgn_perimetr)

**Output:**

Enter some random number = 12.5 The Octagon's Area with given side length { 12.5 } = 754.4417382415921 The Octagon's Perimeter with the given side length { 12.5 } = 100.0

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