Question

1. find the missing segment. give only the number.

Explanation:

Step1: Use the property of parallel lines and proportional segments

According to the theorem of parallel lines dividing line - segments proportionally. Let the missing segment be \(x\). We have the proportion \(\frac{5}{5 + 4}=\frac{x}{18}\).

Step2: Solve the proportion for \(x\)

Cross - multiply: \(5\times18=(5 + 4)x\).
So, \(90 = 9x\).
Divide both sides by \(9\): \(x=\frac{90}{9}\).

Answer:

\(10\)