Question

编写程序根据五边形五个顶点的坐标计算五边形的面积

Answer 1

#include

#include

#include "math.h"

using namespace std;

typedef vector::iterator iter;

double length(iter &iterFir,iter &iterSec)

{

return sqrt(pow(*iterSec-*iterFir,2)+pow(*(iterSec+1)-*(iterFir+1),2));

};

double compute(iter &iterFir,iter &iterSec,iter &iterThi)

{

double a,b,c,d;

a=length(iterFir,iterSec);

b=length(iterSec,iterThi);

c=length(iterThi,iterFir);

if(a+b>c&&a+c>b&&b+c>a)

{

d=(pow(a,2)+pow(c,2)-pow(b,2))/(2*a*c);

d=sqrt(1-pow(d,2));

return (0.5*a*c*d);

}

else

{

ce