% Similar triangles % Copyright (c) Christian Obrecht 2001 box(-4,-5,8.5,5) A = point(0,0) ; B = point(4,0) C1 = circle(A,3) ; C2 = circle(B,3.5) D E intersection(C1,C2) L = line(E,165:) E F intersection(L,C1) G E intersection(L,C2) color(lightgray) draw(C1) ; draw(C2) color(black) draw(A,B,D) color(red) draw(D,F,G)