# C++ Program to Find Area, Perimeter of Rectangle

In this article, you will learn and get code on printing the area and perimeter of a rectangle based on length and breadth entered by user at run-time in C++ programming. Here are the list of approaches used to find area and perimeter of a rectangle:

• Find Area of a Rectangle without using Function
• Area of a Rectangle using Function
• Perimeter of Rectangle without using Function
• Perimeter of Rectangle using Function
• Find Area and Perimeter of a Rectangle using Class and Object

### Area of Rectangle Formula

The formula to calculate area of a rectangle is given below:

`area = len*bre`

Here, len indicates length and bre indicates breadth of rectangle.

### Perimeter of Rectangle Formula

To calculate perimeter of rectangle, use following formula:

`perimeter = 2*(len+bre)`

Here also, len and bre indicates to length and breadth of the rectangle. Now let's move on to the program.

## Find Area of Rectangle

The question is, write a program in C++ to find and print area of a rectangle. The program given below is the answer of this question:

```// C++ Program to Find Area of Rectangle
// ----codescracker.com----

#include<iostream>
using namespace std;
int main()
{
float len, bre, area;
cout<<"Enter Length of Rectangle: ";
cin>>len;
cin>>bre;
area = len*bre;
cout<<"\nArea = "<<area;
cout<<endl;
return 0;
}```

This program was build and run under Code::Blocks IDE. Here is its sample run:

Now enter the length and breadth of rectangle, and press `ENTER` key to see the area based on given length and breadth of rectangle as shown in the output given below:

When user enters length, it gets initialized to len, and when enters breadth, it gets initialized to bre. Using the formula, len*bre gets initialized to area variable, that holds the area of rectangle. Therefore just print its value as output.

### Area of Rectangle using Function

Let's create the same purpose program using a user defined function, areaOfRectangle(). This function takes two arguments and returns a single value. The two arguments are length and breadth, whereas its return value will be the area of rectangle. To learn more about function, you can follow its separate tutorial.

```// Find Area of Rectangle using Function
// ----codescracker.com----

#include<iostream>
using namespace std;
float areaOfRectangle(float, float);
int main()
{
float len, bre, area;
cout<<"Enter Length of Rectangle: ";
cin>>len;
cin>>bre;
area = areaOfRectangle(len, bre);
cout<<"\nArea = "<<area;
cout<<endl;
return 0;
}
float areaOfRectangle(float len, float bre)
{
return (len*bre);
}```

## Find Perimeter of Rectangle

Now let's find and print the perimeter of a rectangle without using function.

```// C++ Program to Find Perimeter of Rectangle
// ----codescracker.com----

#include<iostream>
using namespace std;
int main()
{
float len, bre, per;
cout<<"Enter Length and Breadth of Rectangle: ";
cin>>len>>bre;
per = 2*(len+bre);
cout<<"\nPerimeter = "<<per;
cout<<endl;
return 0;
}```

Here is the sample run of above program:

Now supply the value of length and breadth of a ractangle to find and prints its perimeter as shown in the output given below

### Perimeter of Rectangle using Function

Here is another program that also find and prints perimeter of rectangle using user-defined function.

```// Find Perimeter of Rectangle using Function
// ----codescracker.com----

#include<iostream>
using namespace std;
float perOfRectangle(float, float);
int main()
{
float len, bre;
cout<<"Enter Length and Breadth of Rectangle: ";
cin>>len>>bre;
cout<<"\nPerimeter = "<<perOfRectangle(len, bre);
cout<<endl;
return 0;
}
float perOfRectangle(float len, float bre)
{
return (2*(len+bre));
}```

## Find Area & Perimeter of Rectangle using Class

Now let's combine both and create a single program using class to find area and perimeter of a rectangle. For more detail about classes and objects, you can refer to its separate tutorial.

```// Find Area and Perimeter of Rectangle using Class
// ----codescracker.com----

#include<iostream>
using namespace std;
class CodesCracker
{
private:
float len, bre;
public:
void getData();
float areaOfRect();
float periOfRect();
};
void CodesCracker::getData()
{
cout<<"Enter Length and Breadth of Rectangle: ";
cin>>len>>bre;
}
float CodesCracker::areaOfRect()
{
return (len*bre);
}
float CodesCracker::periOfRect()
{
return (2*(len+bre));
}
int main()
{
CodesCracker c;
float area, per;
c.getData();
area = c.areaOfRect();
per = c.periOfRect();
cout<<"\nArea = "<<area;
cout<<"\nPerimeter = "<<per;
cout<<endl;
return 0;
}```

Here is its sample run with user input of 5 as length and 3 as breadth: