View Code of Problem 28

#include<stdio.h>
#include<math.h>
#define PI 3.14159265
int main()
{
    int a,b,c;
    double t,m;
    scanf("%d%d%d",&a,&b,&c);
    t=acos((double)(a*a+c*c-b*b)/(2*a*c));
    m=fabs(sin(t*180/PI));
    printf("%.2lf\n",1.0/2*a*c*m);
    return 0;
}