By definition, congruent triangles should have all the corresponding sides and all the corresponding angles equal or congruent to each other. Thus, in the given question, all corresponding sides and angles of ΔEFG and ΔE'F'G' should be congruent. But, as we can see clearly it is given that, EF = 10 and E'F'= 12, thus, the corresponding sides EF and E'F' are not equal. Thus, we cannever prove that: