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.

Answer 3

@dan815