The vertices of δabc are a (1, 5), b (3, 9), and c (5, 3). the vertices of δdef are d (−3, 3), e (−2, 5), and f (−1, 2). which conclusion is true about the triangles? a the ratio of their corresponding sides is 1: 3. b they are congruent by the definition of congruence in terms of rigid motions. c the ratio of their corresponding angles is 1: 3. d they are similar by the definition of similarity in terms of a dilation.