Questions: Given: AC ⊥ BD and BD bisects AC.
Prove: ΔABD ≅ ΔCBD.
Step Statement Reason
1 AC ⊥ BD Given
try BD bisects AC
Note: the segment AC is a straight segment.
Transcript text: Given: $\overline{A C} \perp \overline{B D}$ and $\overline{B D}$ bisects $\overline{A C}$.
Prove: $\triangle A B D \cong \triangle C B D$.
\begin{tabular}{|c|c|l|}
\hline Step & Statement & Reason \\
\hline 1 & $\overline{A C} \perp \overline{B D}$ & Given \\
\hline try & $\overline{B D}$ bisects $\overline{A C}$ & \\
\hline
\end{tabular}
Note: the segment $A C$ is a straight segment.
Solution
Solution Steps
Step 1: BD bisects AC
Given that BD bisects AC, we know that AD = CD. This is the definition of a bisector.
Step 2: AC ⊥ BD
Given that AC ⊥ BD, we know that ∠BDA and ∠BDC are right angles. Therefore, ∠BDA ≅ ∠BDC because all right angles are congruent.
Step 3: BD is a common side
BD is a side in both triangles ABD and CBD. Thus, BD ≅ BD by the reflexive property.
Final Answer
Triangle ABD is congruent to triangle CBD by SAS (Side-Angle-Side) congruence. We have two congruent sides (AD≅CD and BD≅BD) and a congruent angle between them (∠BDA ≅ ∠BDC).