\( A B C D \) is a trapezium with parallel sides \( A B=a \mathrm{~cm} \) and \( D C=b \mathrm{~...

\( A B C D \) is a trapezium with parallel sides \( A B=a \mathrm{~cm} \) and \( D C=b \mathrm{~cm}, E \) and \( F \) are the mid-points of the non-parallel sides, find the ratio of \( \operatorname{ar}(A B F E) \) and \( \operatorname{ar}(E F C D) \).