# C program to find the perimeter of a rectangle

## C program to find the perimeter of a rectangle:

In this post, we will learn how to find the perimeter of a rectangle in C programming. The program will take the values as inputs from the user to calculate the perimeter and it will print the value. With this program, you will learn how to take user input values, how to do simple mathematical calculations, and how to print values on the console in C.

### Algorithm to find the perimeter of a rectangle:

To find the perimeter of a rectangle, we need the length and width of the rectangle. We can use the below formula to find the perimeter:

``2 * (length + width)``

So, if we can get the length and width values as inputs from the user, we can calculate its perimeter.

### Example 1: C program to find the perimeter of a rectangle:

Let’s write down the C program to find the perimeter of a rectangle with user input length and width:

``````#include <stdio.h>

int main()
{
float length, width, perimeter;

printf("Enter the length of the rectangle: ");
scanf("%f", &length);

printf("Enter the width of the rectangle: ");
scanf("%f", &width);

perimeter = 2 * (length + width);

printf("Perimeter: %.2f\n", perimeter);
}``````

Here,

• It created three float variables length, width and perimeter.
• It asks the user to enter the length and width of the rectangle. It uses scanf to read the user input numbers and assigns these to length and width variables.
• The perimeter of the rectangle is calculated and assigned it to the perimeter variable.
• The last line is printing the value of the perimeter.

It will print output as below:

``````Enter the length of the rectangle: 12
Enter the width of the rectangle: 13
Perimeter: 50.00``````

### Example 2: C program to find the perimeter of a rectangle by using a separate function:

Let’s use a separate function to find the perimeter. We will create another function that will calculate the perimeter. It will be a separate function and we can call it from any other places we want. Let me show you the program:

``````#include <stdio.h>

float getPerimeter(float length, float width)
{
return 2 * (length + width);
}

int main()
{
float length, width, perimeter;

printf("Enter the length of the rectangle: ");
scanf("%f", &length);

printf("Enter the width of the rectangle: ");
scanf("%f", &width);

printf("Perimeter: %.2f\n", getPerimeter(length, width));
}``````

Here,

• The getPerimeter function is used to calculate the perimeter. It takes the length and the width of the rectangle as its parameters and returns the perimeter of the rectangle.

It will print similar output.