The figure below shows segments ac and ef which intersect at point b. segment af is parallel to segment ec.. which of these facts is used to prove that triangle abf is similar to triangle cbe? . angle afb is congruent to angle ceb because corresponding angles are congruent.. angle afb is congruent to angle ceb because corresponding angles are congruent.. line segment af is congruent to line segment ec because parallel segments are congruent.. line segment ab is congruent to line segment fb because legs of an isosceles triangle are congruent.