Since DEC and DAB share the angle D, and the lines EC and AB are parallel, then we can also see that the angles CED and BAD are congruent. Then, we can prove the similarity between those two triangles thanks to the AA criterion.
Step-by-step explanation: if you divide 9 by 3 it would be 3 and 6 divided by 3 would be 2 so if you multiply 2 by 4 and 3 by 4 and you add them together it will equal 20
