input geom2d; gddU:=0.35cm; beginfig(1); A = Point(0,0); B = Point(6,0); C = Point(0.8,4); T_ABC = Triangle(A,B,C); C_I = InscribedCircle(T_ABC); C_A = EscribedCircle(T_ABC,2); C_B = EscribedCircle(T_ABC,3); C_C = EscribedCircle(T_ABC,1); d_AB = Line(A,B); d_BC = Line(B,C); d_CA = Line(C,A); I = Center(C_I); I_C_A = Center(C_A); I_C_B = Center(C_B); I_C_C = Center(C_C); d_CAA = Line(A,I_C_A); d_CAB = Line(B,I_C_B); d_CAC = Line(C,I_C_C); A_S = AxisOfSimilitude(C_A,C_B,C_C); P_CA = PointOnLineProjection(I_C_A,A_S); P_CB = PointOnLineProjection(I_C_B,A_S); P_CC = PointOnLineProjection(I_C_C,A_S); P_A = Inverse(P_CA,C_A); P_B = Inverse(P_CB,C_B); P_C = Inverse(P_CC,C_C); C_R = RadicalCenter(C_A,C_B,C_C); % les neuf points pour les cercles d’euler (tangent intérieur) % et d’apollonius (tangent extérieur) D1 = Line(C_R,P_A); P1 = LineCircleIntersection(D1,C_A,1); Q1 = LineCircleIntersection(D1,C_A,2); D2 = Line(C_R,P_B); P2 = LineCircleIntersection(D2,C_B,1); Q2 = LineCircleIntersection(D2,C_B,2); D3 = Line(C_R,P_C); P3 = LineCircleIntersection(D3,C_C,2); Q3 = LineCircleIntersection(D3,C_C,1); % le cercle d’apollonius Apol = CircleThreePoints(P1,P2,P3); gddFill Apol withcolor 1.05*Lavender; gddDraw Apol withcolor CadetBlue; % cercle inscrit gddFill C_I withcolor LightBlue; % cercles exinscrits gddFill C_A withcolor PapayaWhip; gddFill C_B withcolor PapayaWhip; gddFill C_C withcolor PapayaWhip; gddDraw d_AB; gddDraw d_BC; gddDraw d_CA; gddDraw d_CAA dashed evenly; gddDraw d_CAB dashed evenly; gddDraw d_CAC dashed evenly; gddDraw T_ABC withpen pencircle scaled 2 withcolor Chocolate; C_E = EulerCircle(T_ABC); gddDraw C_E withcolor Goldenrod; gddDrawPoint P1; gddDrawPoint P2; gddDrawPoint P3; gddDrawPoint Q1; gddDrawPoint Q2; gddDrawPoint Q3; gddMark.llft "A"; gddMark.urt "B"; gddMark.urt "C"; Window(-7,-12,20,15) endfig; end.