Aconjecture and the flowchart proof used to prove the conjecture are shown.

given: a b c d is a parallelogram. prove: angle 1 is supplementary to angle 3. art: parallelogram a b c d. ray d b is drawn and is extended past vertex b. the ray forms an interior angles a d b and d b c and an exterior angle labeled as 3, adjacent to angle d b c. angle a d b is labeled as 1, and angle d b c is labeled as 2.

drag an expression or phrase to each box to complete the proof.

∠1 is supplementary to ∠3.

Step-by-step explanation:

Given information: ABCD is a parallelogram.

Prove: ∠1 is supplementary to ∠3.

Proof:

∠1 = ∠ADB

∠2 = ∠DBC

∠3 = exterior angle adjacent to angle D B C.

Statement                                         Reason

∠2 is supplementary to ∠3           Linear pairs

m∠2+m∠3=180°                             Definition of supplementary angles

                           Alternative interior angles

m∠1+m∠3=180°                              Substitute property of equality

∠1 is supplementary to ∠3            Definition of supplementary angles

Hence proved.

linear pair postulates

i think the correct option is the second option.