#include <stdio.h>
#include <math.h>
typedef struct{
double a;
double b;
double c;
}list;
double area(list t);
int main(void) {
list me = {5,12,13};
double s = area (me);
return 0;
}
double area(list t){
double r;
r = (t.a + t.b + t.c )/2.0;
return sqrt(r
*(r
-t.
a)*(r
-t.
b)*(r
-t.
c)); }
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