We are given AB / DE. Because the lines are parallel and segment CB crosses both lines, we can consider
segment CB a transversal of the parallel lines. Angles
CED and CBA are corresponding angles of transversal
CB and are therefore congruent, so 2CED ZCBA.
We can state C 2C using the reflexive property.
Therefore, AACB- ADCE by the
O AA similarity theorem.
O SSS similarity theorem.
O AAS similarity theorem.
O ASA similarity theorem.