Question

Given line AE and line BD that intersect at point C, the following is an indirect paragraph proof proving that vertical angles ACB and ECD are congruent:

lines AE and BD intersect at point C

Assume ∠ACB and ∠ECD are not congruent. The Vertical Angles Theorem says that vertical angles must be congruent. Since this contradicts the assumption, vertical angles ACB and ECD are congruent.

Is the indirect proof logically valid? If so, why? If not, why not?

Answer 1

Yes. Statements are presented in a logical order using the correct theorems.

Yes. The conclusion was used to contradict the assumption.

No. The conclusion was used to contradict the assumption.

No. The progression of the statements is logically inaccurate.

Answer 2

@AnswerMyQuestions can you help me on this one too?

Answer 3

What do you think?

Answer 4

I dont understand anything about this one

Answer 5

Ok, so the picture shows vertical angles. If you assume ∠ACB and ∠ECD are not congruent when the Vertical Angles Theorem says that vertical angles must be congruent, that is a contradiction.

Answer 6

Reload the page to see what I said.

Answer 7

I did..

Answer 8

So what do you think the answer is?

Answer 9

A contradiction is when statements or ideas go against each other, or oppose each other.

Answer 10

umm.. im still a bit confused...

Answer 11

It gives you the answer in the question. It says: Since this contradicts the assumption, vertical angles ACB and ECD are congruent.

So what's the answer?

Answer 12

Would that be C?

Answer 13

I think...

Answer 14

Alright, do u think I should go for C then?
Or do u need to make sure?

Answer 15

it correct!
Thnx for the help!!!
Medal for u!!!!!!!!!!

Answer 16

Np