# C Program to find diameter, circumference and area of a circle

Category: C Program

Write a C program to enter the radius of a rectangle and find the diameter, circumference and area of a circle.

Formula to find diameter, circumference and area of circle

CIRCUMFERENCE = 2 * π * RADIUS

And we can use operators to implement the same formula in our C program.

Example -

``````Input: Enter radius of the circle: 7
Output: Diameter of circle: 14.000000
Circumference of circle: 43.959999
Area of circle: 153.860001
``````

## C program to find diameter, circumference and area of a circle

``````#include <stdio.h>
#define PI 3.14

void main()
{

printf("Enter radius of the circle: ");

circumference = 2 * PI * radius;

printf("Diameter of circle: %f\n", diameter);
printf("Circumference of circle: %f\n", circumference);
printf("Area of circle: %f", area);
}
``````

Output

``````Enter radius of the circle: 7
Diameter of circle: 14.000000
Circumference of circle: 43.959999
Area of circle: 153.860001
``````