Question

$△ABC\cong △DEF$ and their perimeters are $32$cm and $24$cm respectively. If $AB=10$cm, find $DE$

Answer 1

$\because △ABC\cong △DEF$

$\therefore$ Perimeter of $\frac{△ABC}{△DEF}=\frac{AB}{DE}$

$\Rightarrow \frac{32}{24}=\frac{10}{DE}$

$\Rightarrow DE=\frac{24\times 10}{32}=7.5$cm