PDF Congruent angles worksheet pdf answers answer AC and D is the midpoint of AB.Given: DE ? m.StatementReasons1.Lines l and m are cut by a transversal t, and ?1 are ?3 supplementary anglesGiven2.?2 and ?1 are supplementary anglesDefinition of supplementary angles3.?3 ~= ?2Example 24.?3 and ?2 are corresponding anglesDefinition of corresponding angles5.l ? ACDefinition of ?5.