Write a C algorithm to calculate the area of a circle?

Answer 1

#include<stdio.h>

main()

{

int r;

float area;

clrscr();

printf("enter the value of r\n");

scanf("%d",&r);

area=3.142*r*r;

printf("area of circle=%f\n",area);

getch();

}

Answer 2

inline double area(const double radius) { return radius * radius * 3.14159;}