Question

In the pair of similar trapezoids, what is the length of side DA?

Answer 1

$\dfrac{|EH|}{|GH|}=\dfrac{|AD|}{|CD|}\\\\ \dfrac{15}{20}=\dfrac{|AD|}{60}\\ \dfrac{3}{4}=\dfrac{|AD|}{60}\\ 4|AD|=180\\ |AD|=45$