Chapter 4, Problem 10CCSR

To determine

To find which expression repression represents AB.

Answer to Problem 10CCSR

Option F is correct.

Explanation of Solution

Given:

Diagram of $△ABC$ and $△DEF$ are similar provided in textbook.

Calculation:

Diagram of $△ABC$ and $△DEF$ are similar provided in textbook.

In $△ABC$

  $\begin{array}{l}AC=q\\ BC=r\\ AB=?\end{array}$

In $△DEF$

  $\begin{array}{l}DF=s\\ EF=t\\ DE=u\end{array}$

Formula for the ratio:

  $\frac{AB}{DE}=\frac{AC}{DF}=\frac{BC}{EF}$

This implies that,

  $\frac{AB}{u}=\frac{q}{s}=\frac{r}{t}$

Consider the first and second equation:

  $\frac{AB}{u}=\frac{q}{s}$

This implies that,

  $AB=\frac{qu}{s}$

Therefore, correct answer is F.