input constantes; input geometriepoint1; beginfig(1); affixe.A(u*(1,1))so; affixe.E(u*(6,1))se; affixe.C(1/2[z.A,z.E])s; affixe.B(z.C rotatedabout(z.A,60))n; affixe.D(z.C rotatedabout(z.E,-60))n; draw triangle(A,B,C); draw triangle(C,D,E); endfig; beginfig(2); affixe.B(u*(1,1)); affixe.I(u*(7,1)); affixe.J(u*(8,4)); affixe.K(z.J shifted(z.B-z.I)); path cc; cc=z.B--z.I--z.J--z.K--cycle; draw hachurage(cc,120,0.5,1); draw cc; affixe.O(1/2[z.B,z.J]); affixe.V((0,0)); path cd,ce; cd=cercle(V,1cm); ce=cd yscaled0.25; fill (ce shifted z.O) withcolor blanc; draw ce shifted z.O; affixe.A(point(0.15*length ce) of (ce shifted z.O))n; affixe.D(point(0.65*length ce) of (ce shifted z.O))n; draw (point(0.5*length ce) of (ce shifted z.O))--(point(0.5*length ce) of (ce shifted (z.O shifted(u*(0,-3))))) dashed evenly; affixe.E(2[z.D,z.A])e; affixe.C(z.D shifted(u*(0,-3)))so; draw ce shifted(z.O shifted(u*(0,-3))) dashed evenly; draw z.D--z.C dashed evenly; draw (point(0) of (ce shifted(z.O shifted(u*(0,-3)))))--(point(0) of (ce shifted z.O)) dashed evenly; affixe.Z(z.E shifted(u*(0,2))); affixe.Y(demidroite(C,A,10) intersectionpoint demidroite(E,Z,10))n; draw z.D--z.E--z.Y--z.A; draw z.A--z.C dashed evenly; draw codeperp(C,D,A,5); draw codeperp(A,E,Y,5); endfig; beginfig(3); affixe.A(u*(1,1))so; affixe.B(u*(5,1))se; affixe.C(u*(6.5,2.5))e; affixe.E(u*(1,5))o; affixe.F(z.B shifted (z.E-z.A))se; affixe.G(z.C shifted(z.E-z.A))ne; affixe.D(z.A shifted(z.C-z.B))se; affixe.H(z.D shifted(z.E-z.A))no; draw z.A--z.B--z.C--z.G--z.H--z.E--cycle; draw z.E--z.F--z.G; draw z.F--z.B; draw z.H--z.D--z.A dashed evenly; draw z.D--z.C dashed evenly; endfig; end