Which of the following completes the proof? Given: Segment AC is perpendicular to segment BD Triangles ABC and EDC are formed from segments BD and AC, in which point C is between points B and D and point E is between points A and C.

Prove: ΔACB ~ ΔECD

Reflect ΔECD over segment AC. This establishes that ∠ACB ≅ ∠E'C'D'. Then, _. This establishes that _. Therefore, ΔACB ~ ΔECD by the AA similarity postulate.