Complete the proof 1 Given Line AB intersects line DC at point B LAEB and DEC are straight angles Prove LAEC DEB 10 Statements E Reasons 1 1 2 ZAEC is supplementary to CEB 2 3 ZDEB is supplementary to CEB 3 Def of Supplementary Zs 4 4 Supplements Theorem a ZAEB and DEC are straight angles b Substitution c Angle Addition Postulate d Given e Addition Property of Equality f Linear Pair Theorem g ZAEC is congruent to ZDEB B