C

c program to find area of circle

#include <stdio.h>
#define PI 3.142
int main(){
    float R, A;
    printf("Enter the radius: 
");
    scanf("%f", &R);
    A = PI * R * R;
    printf("Area is: %f
", A);
    
}

Area of a Circle in C Programming

#include<stdio.h>
int main()
{
    double R, A;
    scanf("%lf", &R);
    A = 3.14159 * R * R;
    printf("A=%.4lf
", A);
    return 0;
}