Ineed with problem number 12 i don’t know what it’s asking for!

Step-by-step explanation:

I understand your confusion. The problem is that Benito didn't make any errors.

Begin by drawing a line from B to D

You get 2 triangles.

Copy Benito's first two statements, which according the diagram are correct.

The third fact is that BD = BD.

The two triangles are congruent by SSS.

If the two triangles are congruent then <A = <C by corresponding parts of congruent triangles are congruent.

So there aren't any errors. There are a couple of missing steps. One of the top answers on this board, when he encounters a problem like this one, says "Ask your teacher to prove that <A does not equal <C" In other words what is wrong with problem -- unless it is that you need a couple of extra steps.

They certainly available and they do not make Benito's statement untrue.