Question

1. a • — ? — • b — 5 — • c ←—— 12 ——→

Explanation:

Step1: Define the segment relationship

From the diagram, we know that the length of \( AC \) is the sum of the length of \( AB \) and the length of \( BC \). So, \( AC = AB + BC \). We are given \( AC = 12 \) and \( BC = 5 \), and we need to find \( AB \).

Step2: Solve for \( AB \)

Rearranging the formula from Step 1 to solve for \( AB \), we get \( AB = AC - BC \). Substituting the given values, \( AC = 12 \) and \( BC = 5 \), we have \( AB = 12 - 5 \).

Step3: Calculate the result

Performing the subtraction, \( 12 - 5 = 7 \).

Answer:

7