GEOMETRY PROOF [TWO COLUMN] on Perpendicular Lines.

[geometrykid]

Write a two-column proof.
Given: angle 1 congruent to angle 2, l perpendicular to n
Prove: l perpendicular to p

here's the diagram:

what i got ( i think i'm missing something .... )
statements (reasons)
1. angle 1 congruent to angle 2 (given)
2. p parallel to n (converse of the alternate interior angles theorem)
3. l is perpendicular to p (perpendicular transversal theorem)

Not sure what...I mean a proof in .. 3 steps? ;/

 

[Mrspi]

Write a two-column proof.
Given: angle 1 congruent to angle 2, l perpendicular to n
Prove: l perpendicular to p

what i got ( i think i'm missing something .... )
statements (reasons)
1. angle 1 congruent to angle 2 (given)
2. p parallel to n (converse of the alternate interior angles theorem)
3. l is perpendicular to p (perpendicular transversal theorem)

Not sure what...I mean a proof in .. 3 steps? ;/

Well, let's see...

You have shown that p || n.

Now...you are GIVEN that l is perpendicular to n.

You should have a theorem that says that "in a plane, if a line is perpendicular to one of two parallel lines, then it is perpendicular to the other one also."

If l is perpendicular to n (which is given) and n || p, which you proved, then l is perpendicular to p, using the above theorem as a justification.

 

[geometrykid]

Well, let's see...

You have shown that p || n.

Now...you are GIVEN that l is perpendicular to n.

You should have a theorem that says that "in a plane, if a line is perpendicular to one of two parallel lines, then it is perpendicular to the other one also."

If l is perpendicular to n (which is given) and n || p, which you proved, then l is perpendicular to p, using the above theorem as a justification.

sooo this theorem: perpendicular transversal theorem

is wrong ?
i don't understand why...

 

[stapel]

sooo this theorem: perpendicular transversal theorem is wrong ? i don't understand why...

I'm sorry, but I don't understand what you're saying here...? In which post did somebody say that a proven theorem was actually invalid (unproven and incorrect, "wrong")...?

Please clarify. Thank you!

Eliz.

 

[geometrykid]

What you told me was wrong.
My first answer was correct.