Question

△abd ≅ △cbd, find ab. ac = 12 ab = ?

Explanation:

Step1: Recall congruent triangle property

Since $\triangle ABD \cong \triangle CBD$, their corresponding sides are equal. So, $AB = CB$.

Step2: Use segment addition postulate

We know that $AC = AB + CB$ (segment addition postulate). Substituting $CB$ with $AB$ (from Step 1), we get $AC = AB + AB = 2AB$.

Step3: Solve for AB

Given $AC = 12$, we have the equation $2AB = 12$. Dividing both sides by 2, we get $AB=\frac{12}{2}=6$.

Answer:

6