Question

If $△ABC\sim △DEF$ and $AB=2.4cm$, $DE=1.6cm$, find the ratio of $△ABC$ and $△DEF$.

Answer 1

For similar triangles,

ratio of area of triangles = ratio of square of corresponding sides

Hence, $\frac{Ar.△ABC}{Ar.△DEF}=\frac{A{B}^2}{D{E}^2}$

$\frac{Ar.△ABC}{Ar.△DEF}=\frac{A{B}^2}{D{E}^2}$

$\frac{Ar.△ABC}{Ar.△DEF}=\frac{2.4\times 2.4}{1.6\times 1.6}$

$\frac{Ar.△ABC}{Ar.△DEF}=\frac{9}{4}$