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°

statement justification
line bc is parallel to line ed given
m∠abc = 70° given
m∠ced = 30° given
m∠abc = m∠bed corresponding angles theorem
m∠bec + m∠ced = m∠bed angle addition postulate

m∠bec = 40° subtraction property of equality

which of the following accurately completes the missing statement and justification of the two-column proof?
m∠bec + 30° =70°; substitution property of equality
m∠bec + 30° = 70°; addition property of equality
m∠bec + 40° = 70°; substitution property of equality
m∠bec + 40° = 70°; addition property of equality