Lines BC and ED are parallel. They are intersected by transversal AE, in which point B lies between points and E. They are also intersected by transversal EC. Angle ABC measures 70 degrees. Angle CED measures 30 degrees. Given: line BC is parallel to line ED
m∠ABC = 70°
m∠CED = 30°

Prove: m∠BEC = 40°

StatementJustification
line BC is parallel to line EDGiven
m∠ABC = 70°Given
m∠CED = 30°Given

m∠BEC + m∠CED = m∠BEDAngle Addition Postulate
m∠BEC + 30° = 70°Substitution Property of Equality
m∠BEC = 40°Subtraction Property of Equality

Which of the following accurately completes the missing statement and justification of the two-column proof?
m∠ABC = m∠CED; Corresponding Angles Theorem
m∠ABC = m∠CED; Alternate Interior Angles Theorem
m∠ABC = m∠BED; Corresponding Angles Theorem
m∠ABC = m∠BED; Alternate Interior Angles Theorem