Answer:
Diana is correct Joby is not.
Step-by-step explanation:
To prove that vertical angles are congruent.
DIana started with linear pair property of supplementary angles for two lines
and used transitive property to prove that vertically opposite angles are equal
Hence Diana proof is correct.
But Joby's proof contains these following errors
Instead of proving vertical angles equal, he has used them in the first step as given. This is wrong Similarly second statement also is to be proved but he simply stated without any justification
