.geometry "version 0.40";
v1 = .free(-0.182635, 0.432455, "A");
v2 = .free(0.122754, 0.142036, "B");
v3 = .free(0.158683, -0.148383, "C");
v5 = .free(-0.57485, -0.106467, "D");
l1 = .l.vv(v1, v2, .in);
l2 = .l.vv(v2, v3, .in);
l3 = .l.vv(v3, v5, .in);
l4 = .l.vv(v5, v1, .in);
l5 = .l.vv(v1, v3, .yellow);
l6 = .l.vv(v2, v5, .red);
v6 = .v.ll(l1, l3, "E");
v7 = .v.ll(l4, l2, "F");
l7 = .l.vv(v5, v7);
l8 = .l.vv(v7, v3);
l9 = .l.vv(v5, v6);
l10 = .l.vv(v1, v6);
l11 = .l.vv(v7, v6, .magenta);
v8 = .v.vvmid(v1, v3, .in);
v9 = .v.vvmid(v2, v5, .in);
v10 = .v.vvmid(v7, v6, .in);
c1 = .c.vv(v10, v7, .magenta);
c2 = .c.vv(v8, v3, .yellow);
c3 = .c.vv(v9, v2, .red);
.text("Coaxial Circles.  Given a complete
quadrilateral ABCDEF as in the diagram, the
circles whose diameters are the diagonals
AC, BD, and EF are coaxial -- that is, all
three meet at two points.", .l0);