Why is my program not returning value after the decimal?

This is the code in C :

#include <stdio.h>
#define PI 3.142857
int area(float);
int main(int argc, char const *argv[])
{
    float b,c;
    printf("Enter the radius of the circle: ");
    scanf("%f",&b);
    c =area(b);
    printf("The area of the circle is : %f",c);
    return 0;
}
int area(float r){
    float a;
    a = PI * r *  r;
    return a;
}

For example if I write the input as 3 , it should display 28.26 but is displaying the output as 28.000000.
What is wrong in the code?

>Solution :

Return float instead of int

float area(float r){
    float a;
    a = PI * r *  r;
    return a;
}