Question

If ∆ABC ∼ ∆DEF such that 2 AB = DE and BC = 6 cm, find EF.

Answer 1

$\because$ ∆ABC ∼ ∆DEF

$$\begin{gathered} \therefore \frac{AB}{DE}=\frac{BC}{EF} \\ \Rightarrow \frac{1}{2}=\frac{6}{EF} \\ \Rightarrow EF=12\mathrm{cm} \end{gathered}$$