NULL;
AB := evalm(B-A); BC := evalm(C-B); a := 10;


                               10
vectAB := arrow(A, AB, width = 0.7e-1, head_length = .1, color = blue); vectBC := arrow(B, BC, width = 0.7e-1, head_length = .1, color = blue); ptOrig := pointplot(B, thickness = 5); dAbs := seq([evalm(AB*t+BC*k+B)[1], evalm(AB*t+BC*k+B)[2], t = -a .. a], k = -a .. a); quadAbs := plot({dAbs}, color = red); dOrd := seq([evalm(AB*k+BC*t+A)[1], evalm(AB*k+BC*t+A)[2], t = -a .. a], k = -a .. a); quadOrd := plot({dOrd}, color = red);
display({ptOrig, quadAbs, quadOrd, vectAB, vectBC}, view = [-a .. a, -a .. a]);