## C Program To Find Area Of Circle

Ex: write a C program to find Area of the circle. How to write a C program to find area of circle. C program to find area of circle.

Input from user:

Enter the radius of the circle: 5

Expected Output:

Area of circle is: 78.500000

To find area of circle we need to use pi(π). Because pi(π) represents  the ratio of the circumference of a circle to its diameter.

Step by step logic of the program:

1. First  we need to declare two variable's. One for accepting radius of the circle from user and second one is for store the area of circle.

2. So declare variable's  r for radius of the circle and a for  area of the circle.

3. To find area use area of circle's simple logic which π*r^2(pi r square).

4. Here pi's value is 3.14. so we will write a=3.14*r*r.(here r=5)

5. Last we will print value of a(area of circle) on the output screen.

Program:

#include<stdio.h>
int main()
{

int r;
float a;

printf("enter the radius of the circle:\n");
scanf("%d",&r);

a=3.14*r*r;

printf("Area of circle is %f",a);

return 0;
}

Above program shows the following output: