Read the proof.
Given: AB I DE
Prove: AACB - ADCE
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 _CED CBA. We can state C
C using the reflexive property. Therefore, AACB -
ADCE by the
E
AA similarity theorem.
SSS similarity theorem.
AAS similarity theorem.
ASA similarity theorem.