Side Side Side postulate states that if three sides of one triangle are congruent to three sides of another triangle, then these two triangles are congruent.
$$\triangle ABC \cong \triangle XYZ $$
- All 3 sides are congruent
- ZX = CA (side)
- XY = AB (side)
- YZ = BC (side)
- Therefore, by the Side Side Side postulate, the triangles are congruent
Given:$$ AB \cong BC, BD$$ is a median of side AC.
Prove:$$ \triangle ABD \cong \triangle CBD $$