Question

In the similar triangles below, what is the length of AB?

Answer 1

Given:

There are given two triangles, ABC and DEF.

Where,

$\begin{gathered} AC=6cm \\ BC=4cm \\ DE=15cm \\ DF=18cm \end{gathered}$

Explanation:

To find the value of two congruent triangles, we need to use the ratio properties:

So,

From the given congruent triangle:

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

Then,

Put the all values into the above ratio expression:

So,

$\begin{gathered} \begin{equation*} \frac{AB}{DE}=\frac{AC}{DF} \end{equation*} \\ \frac{AB}{15}=\frac{6}{18} \\ \frac{AB}{15}=\frac{1}{3} \\ 3AB=15 \\ AB=\frac{15}{3} \\ AB=5 \end{gathered}$

Final answer:

Hence, the correct option is D.