Question 4
Triangle $ABC$ has $AB=AC$. Point $D$ is on $AB$, with $BA=3BD$; point $E$ is on $AC$, with $CA=3CE$. Which congruence condition directly proves triangles $EBC$ and $DCB$ congruent? The conditions are SSS, ASA, AAS, SAS, HL: S means side, A means angle, H means hypotenuse and L means leg. HL applies only to right triangles.