lrj训练指南 P259
//==================================================================== Point getP(Point A,Point B,Point C) { double a1=Angle(A-B,C-B); Vector v1=Rotate(C-B,a1/); double a2=Angle(A-C,B-C); Vector v2=Rotate(B-C,-a2/); return GetLineIntersection(B,v1,C,v2); } int main() { int T; Point A,B,C,D,E,F; scanf("%d",&T); while(T--) { A.read(); B.read(); C.read(); D=getP(A,B,C); E=getP(B,C,A); F=getP(C,A,B); printf("%.6lf %.6lf %.6lf %.6lf %.6lf %.6lf\n",D.x,D.y,E.x,E.y,F.x,F.y); } }