##### area and circumference of circle in C

This program is used for simple calculation of circle.

If we want to find area of circle which is **π.r.r**

or circumference i.e **2.π.r**

the we can use this code its easy

// 1 line comment in the program

/* multi line comment

ok

*/

area and circumference of circle in C

```
#include<stdio.h>
// its a Pre-processor Directives used for Defining identifiers from Standard Libraries
#define PI 3.14
/*we can define anything if we want to use it again & again like if we write "PI" anywhere it will be treated as 3.14 */
int main() {
//main function started
/* function is always like funtype functioname() { }
e.g. int main() { } */
float Circum, Area, rad;
// we use/define 3 variables and their type like Float , int , long, double
printf("\n Hi, please Enter the Radius=");
// simple output
scanf("%f",&rad);
// above code is used for read the value scanf() %f is float type &rad its a variable which is declared by user
Circum=2*PI*rad;
//formula of circum and area
Area=PI*rad*rad;
// output
printf("\n if the radius is=%.2f",rad);
// %.2f the output with 2 correct decimal place
printf("\n then Circumference of the circle will be=%.2f",Circum);
printf("\n and Area of the circle will be=%.2f",Area);
return 0;
}
```

output is

area and circumference of the circle

if you don’t know about circle then

click here

Hi, please Enter the Radius=14.7

if the radius is=14.70

then Circumference of the circle will be=92.32

and Area of the circle will be=678.52