## C Program to Find Diameter, Circumference and Area of Circle Using Function

In this program, we will find diameter, circumference and area of a circle using function.

##### Source Code
#include <stdio.h>
#include <math.h>
double getDiameter(double radius);
double getCircumference(double radius);
double getArea(double radius);
int main()
{
float radius, dia, circ, area;
printf("Enter radius of circle: ");
scanf("%f", &radius);

dia  = getDiameter(radius);
circ = getCircumference(radius);
area = getArea(radius);

printf("Diameter of the circle = %.2f units\n", dia);
printf("Circumference of the circle = %.2f units\n", circ);
printf("Area of the circle = %.2f sq. units", area);
return 0;
}
double getDiameter(double radius)
{
return (2 * radius);
}
double getCircumference(double radius)
{
return (2 * M_PI * radius); // M_PI = PI = 3.14 ...
}
double getArea(double radius)
{
return (M_PI * radius * radius); // M_PI = PI = 3.14 ...
}
##### Output
Enter radius of circle: 12.3
Diameter of the circle = 24.60 units
Circumference of the circle = 77.28 units
Area of the circle = 475.29 sq. units

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