#include <stdio.h>
#include<math.h>

float squarearea(float side);
float rectanglearea(float a,float b);
float circlearea(float rad);

int main() {
    float a=5;
    float b=10;
    
   printf("area is : %f",circlearea(a));
    return 0;
}

float squarearea(float side) {
    return side * side;
}

float rectanglearea(float a,float b) {
    return  a * b;
}

float circlearea(float rad) {
    return 3.14 * rad * rad;
}