Va 11178 Morley's theorem calculation ry

Source: Internet
Author: User

Calculation ry: the most basic calculation ry, differential product Rotation

Morley's Theorem

Time limit:3000 Ms Memory limit:Unknown 64bit Io format:% LLD & % LlU

Submit status


Problem d
Morley's Theorem
Standard Input

Output:Standard output

Morley's theorem states that the lines trisecting the angles of an arbitrary plane triangle meet at the vertices of an equilateral triangle. for example in the figure below the tri-sectors of angles A, B and C has intersected and created an equilateral triangle def.


Of course the theorem has various generalizations, in the particle if all of the Tri-sectors are intersected one obtains four other equilateral triangles. but in the original theorem only tri-sectors nearest to BC are allowed to intersect to get point D, tri-sectors nearest to Ca are allowed to intersect point E and tri-sectors nearest to AB are intersected to get point F. trisectorlike BD and CE are not allowed to intersect. so ultimately we get only one equilateral triangle def. now your task is to find the Cartesian coordinates of D, E and F given the coordinates of A, B, and C.



First line of the input file contains an integer N (0 <n <5001) which denotes the number of test cases to follow. each of the next lines contain six integers. this six integers actually indicates that the Cartesian coordinates of point A, B and C are respectively. you can assume that the area of Triangle ABC is not equal to zero, and the points A, B and C are in counter clockwise order.

Outputfor each line of input you shoshould produce one line of output. this line contains six floating point numbers separated by a single space. these six floating-point actually means that the Cartesian coordinates of D, E and F are respectively. errors less than will be accepted.


Sample input output for sample input
1 1 2 2 1 2 
0 0 100 0 50 50

1.316987 1.816987 1.183013 1.683013 1.366025 1.633975

56.698730 25.000000 43.301270 25.000000 50.000000 13.397460


Problemsetters: Shahriar Manzoor

Special thanks: Joachim Wulff



Root: prominent problemsetters: Shahriar Manzoor

Root: aoapc I: Beginning algorithm contests -- Training Guide (rujia Liu): Chapter 4. Geometry: geometric computations in 2D: Examples

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#include <cmath>using namespace std;const double eps=1e-8;int dcmp(double x){    if(fabs(x)<eps) return 0; else return (x<0)?-1:1;}struct Point{    double x,y;    Point(double _x=0,double _y=0):x(_x),y(_y){}};Point operator+(Point A,Point B) {return Point(A.x+B.x,A.y+B.y);}Point operator-(Point A,Point B) {return Point(A.x-B.x,A.y-B.y);}Point operator*(Point A,double p) {return Point(A.x*p,A.y*p);}Point operator/(Point A,double p) {return Point(A.x/p,A.y/p);}Point A,B,C;double Dot(Point A,Point B) {return A.x*B.x+A.y*B.y;}double Length(Point A) {return sqrt(Dot(A,A));}double Angle(Point A,Point B) {return acos(Dot(A,B)/Length(A)/Length(B));}double angle(Point v) {return atan2(v.y,v.x);}double Cross(Point A,Point B) {return A.x*B.y-A.y*B.x;}Point Rotate(Point A,double rad){    return Point(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));}Point GetLineIntersection(Point p,Point v,Point q,Point w){    Point u=p-q;    double t=Cross(w,u)/Cross(v,w);    return p+v*t;}Point getD(Point A,Point B,Point C){    Point v1=C-B;    double a1=Angle(A-B,v1);    v1=Rotate(v1,a1/3);    Point v2=B-C;    double a2=Angle(A-C,v2);    v2=Rotate(v2,-a2/3);    return GetLineIntersection(B,v1,C,v2);}int main(){    int T_T;    scanf("%d",&T_T);    while(T_T--)    {        for(int i=0;i<3;i++)        {            double x,y;            scanf("%lf%lf",&x,&y);            if(i==0) A=(Point){x,y};            else if(i==1) B=(Point){x,y};            else if(i==2) C=(Point){x,y};        }        Point D=getD(A,B,C);        Point E=getD(B,C,A);        Point F=getD(C,A,B);        printf("%.6lf %.6lf %.6lf %.6lf %.6lf %.6lf\n",D.x,D.y,E.x,E.y,F.x,F.y);    }    return 0;}

Va 11178 Morley's theorem calculation ry

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.