Question

In the figure, $DE\parallel BC$.
Given that $AD=\frac{1}{2}BD$, calculate $DE$, if $BC=4.5cm$.

• A. $DE=1.5cm$
• B. $DE=1.9cm$
• C. $DE=1.6m$
• D. $DE=2.5cm$

Answer 1

The correct option is A $DE=1.5cm$

$AD:DB=1:2$

$AD:AB=1:3$

$\Rightarrow DE:BC=1:3$

$DE:4.5=1.3$

$\Rightarrow 1.5:4.5=1:3$

$\Rightarrow \therefore DE=1.5cm$