# omfg! proofs!

• 10-29-2005, 06:40 PM
Teowulf
omfg! proofs!
In geometry, i am currently learning about proofs. I hate them so freaking much. Can anyone tell me what the use of them in life is. Also, what is the differnce between 2 line segments that are congruent and 2 line segments that are equal?
• 10-29-2005, 06:42 PM
FrozenIpaq
There really isn't any real-life usage of proofs as they are just justifications using theroms. In the "real world" this is something that might only involve those who utilize angles (builders and such)
• 10-29-2005, 06:44 PM
Teowulf
Quote:

Originally Posted by FrozenIpaq
There really isn't any real-life usage of proofs as they are just justifications using theroms. In the "real world" this is something that might only involve those who utilize angles (builders and such)

dude, my dad's an architect and my friends dad is a builder, and they have never used them before on any of their projects
• 10-29-2005, 06:45 PM
FrozenIpaq
Quote:

Originally Posted by billythekilly
dude, my dad's an architect and my friends dad is a builder, and they have never used them before on any of their projects

Well, they must know the theorms which are part of proofs ;) Proofs themselves are not used to my knowledge
• 10-29-2005, 06:46 PM
Zx30
What the hell? I don't remember proofs when i was in Geometry.
• 10-29-2005, 06:49 PM
MagicianFB
Geometry is useful, but proofs aren't.
• 10-29-2005, 07:04 PM
foXtrot
Proofs are the way of showing that a certain mathematical idea is correct. Also people are taught mathematics in school so that they improve their logical abilities and make them solve problems more efficiently.
• 10-29-2005, 10:11 PM
Cheezwiz
My geometry teacher a couple a years back told me the whole reason we did proofs were to learn to think deductively, and it kinda worked :dry:
• 10-30-2005, 03:42 AM
Teowulf
Quote:

Originally Posted by MagicianFB
Geometry is useful, but proofs aren't.

i concur. Can anyone tell me the answer to the second part of my question?
• 10-30-2005, 04:22 AM
Pseudo ANIMALISTIC
Quote:

Originally Posted by billythekilly
In geometry, i am currently learning about proofs. I hate them so freaking much. Can anyone tell me what the use of them in life is. Also, what is the differnce between 2 line segments that are congruent and 2 line segments that are equal?

First, certain proofs are useful...
Like, being asked to prove the cosine rule...
It would involve quite a bit of algebra and all..... and it makes sense to make a proof for it-- to make absolute sure that you understand WHY the rule is correct.
However, those gay proofs which are like this:

Prove that points A and B are on a line.
1) By theorem 1.74 proved by corollary 1.32 there must be so and so.
2) Using the logic of theorem 2.31 with.....
3) Postulate 13...

And you can see how useless it gets by the step.. (This is, literally, the kind of proofs we had to deal with in geometry at my school!)

Other than those kinds of proofs, ones that involve using Algebra or mathematics to prove rules and theorems and whatever are more useful..

And to your second question, as far as I know congruent means the same in shape and magnitude...
I barely remember anything from geometry, but if that's anything like vector algebra it involves two lines pointing in the same direction, making | and - not congruent... but I think my thought involves a different topic, I don't know..
Equal would just be having equal magnitude, anyway.
• 10-30-2005, 06:02 AM
Teowulf
Quote:

Originally Posted by Pseudo ANIMALISTIC
And to your second question, as far as I know congruent means the same in shape and magnitude...
I barely remember anything from geometry, but if that's anything like vector algebra it involves two lines pointing in the same direction, making | and - not congruent... but I think my thought involves a different topic, I don't know..
Equal would just be having equal magnitude, anyway.

But if 2 segments are equal. Doesn't it mean that they're the same line?