triangle help??

Write a graphics program that prompts
the user to enter graphics objects using the mouse or/and the keyboard.
Draw these graphics objectsq make calculations and print out the results .
Your program must be tested with an example given after every task.
13. Enter a triangle and find a point placed inside it

what i do:

Code:

#include <cmath>
using namespace std;
#include "ccc_win.h"

int ccc_win_main()

{
    
    //imput 3 points
    Point a=cwin.get_mouse("Click on the first point:");
    cwin << a;
    Point b=cwin.get_mouse("Click on the second point:");
    cwin << b;
    Point c=cwin.get_mouse("Click on the third point:");
    cwin << c;
    
    // lines
    Line l1(a,b);
    Line l2(b,c);
    Line l3(c,a);
    
    // geting coordinates of the points
    double x1=a.get_x();
    double y1=a.get_y();
    double x2=b.get_x();
    double y2=b.get_y();
    double x3=c.get_x();
    double y3=c.get_y();
    
    // determine the length of the external sides
    double dist1=sqrt(sqrt(x1-x2) + sqrt(y1-y2));
    double dist2=sqrt(sqrt(x2-x3) + sqrt(y2-y3));
    double dist3=sqrt(sqrt(x3-x1) + sqrt(y3-y1));
    
    //result triangle
    cwin << a << b << c << l1 << l2 << l3;
    
    Point d=cwin.get_mouse("Click on the trinagle:");
    
    double x4=d.get_x();
    double y4=d.get_y();
    
    Line l4(a,d);
    Line l5(b,d);
    Line l6(c,d);
    
    // determine the length of the internal lines
    double dist4=sqrt(sqrt(x1-x4) + sqrt(y1-y4));
    double dist5=sqrt(sqrt(x2-x4) + sqrt(y2-y4));
    double dist6=sqrt(sqrt(x3-x4) + sqrt(y3-y4));
    
    // limits the point in the range of the triangle

double s=sqrt((dist1+dist2-dist3)*(dist1-dist2+dist3)*(-dist1+dist2+dist3)*(dist1+dist2+dist3))*0.25;
double s1=sqrt((dist1+dist5-dist4)*(dist1-dist5+dist4)*(-dist1+dist5+dist4)*(dist1+dist5+dist4))*0.25;
double s2=sqrt((dist2+dist6-dist5)*(dist2-dist6+dist5)*(-dist2+dist6+dist5)*(dist2+dist6+dist5))*0.25;
double s3=sqrt((dist3+dist4-dist6)*(dist3-dist4+dist6)*(-dist3+dist4+dist6)*(dist3+dist4+dist6))*0.25;  
 

if (fabs(s-(s1+s2+s3))<1e-6)
cwin << d;
else
cwin <<  Message (Point(0,0),"the point must be inside the triangle!");
    
 
 return 0;   
}

So what's your question?

Originally Posted by Salem

So what's your question?

My question is:

why when i click inside the triangle(the 4th click) the point doesn't appear?

Since when has this:

Code:

double dist4=sqrt(sqrt(x1-x4) + sqrt(y1-y4));

been the distance formula? You're probably getting NaN all over the place.

Originally Posted by tabstop

Since when has this:

Code:

double dist4=sqrt(sqrt(x1-x4) + sqrt(y1-y4));

been the distance formula? You're probably getting NaN all over the place.

what is NaN? I didn't understand you very well.I got this formula from another place in the net,

NaN = Not a number.

You didn't get that formula. You got the formula sqrt((x1-x4)*(x1-x4) + (y1-y4)*(y1-y4)), which is rather different. (That is to say, squares inside, not square roots.)

Originally Posted by tabstop

NaN = Not a number.

You didn't get that formula. You got the formula sqrt((x1-x4)*(x1-x4) + (y1-y4)*(y1-y4)), which is rather different. (That is to say, squares inside, not square roots.)

THANKS A LOT MAN, YOUR ADVICE WAS SUPER USEFUL TO ME!!!