Question

Diana and Joby wrote the following proofs to prove that vertical angles are congruent. Who is correct?

Answer 1

Diana's Proof

Statement Justification
∠1 + ∠2 = 180° Definition of Supplementary Angles
∠1 + ∠4 = 180° Definition of Supplementary Angles
∠1 + ∠2 = ∠1 + ∠4 Transitive Property of Equality


Joby's Proof

Statement Justification
∠2 = ∠4 Vertical angles are congruent.
∠1 = ∠3 Vertical angles are congruent.
Vertical angles are congruent. Vertical Angle Theorem

Answer 2

Diana is correct, but Joby is not.

Both Diana and Joby are correct.

Neither Diana nor Joby is correct.

Joby is correct, but Diana is not.