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

float triangleArea(float a, float b, float c) {
    float s = (a + b + c) / 2;
    return sqrt(s * (s - a) * (s - b) * (s - c));
}

int main() {
    float a, b, c;

    printf("Enter 3 sides: ");
    scanf("%f %f %f", &a, &b, &c);

    printf("Area = %.2f\n", triangleArea(a, b, c));

    return 0;
}