Official Everybody Edits Forums

TrappedTime

Guest

Re: If you like/understand geometry click here

So using your 'dot product' math there comes a contradiction to the geometry of the situation...
Hmm...

Twipply

Guest

Re: If you like/understand geometry click here

So using your 'dot product' math there comes a contradiction to the geometry of the situation...
Hmm...

As I said, some of the lines are not at 90 degrees to each other.   In fact, I'm not sure any of them are.

You need to realise that the plane EBCH is NOT a square, it's a rectangle.   If you want me to explain further, I can, just ask.

~200 posts~

Last edited by Twipply (Aug 6 2011 9:02:01 am)

TrappedTime

Guest

Re: If you like/understand geometry click here

Oh wow... I can't believe I missed this.

The diagonals for the faces are not equal to the edges, thusfore they produce rectangles...
Wow I was ompletely wrong.

But could you imagine, 4 perpendicular lines, LOL.

EDIT: But then that doesn't account for all the other rectangles... How can there be rectangles if it's a regular cube?

Last edited by TrappedTime (Aug 6 2011 9:05:17 am)

Twipply

Guest

Re: If you like/understand geometry click here

Oh wow... I can't believe I missed this.

The diagonals for the faces are not equal to the edges, thusfore they produce rectangles...
Wow I was ompletely wrong.

But could you imagine, 4 perpendicular lines, LOL.

EDIT: But then that doesn't account for all the other rectangles... How can there be rectangles if it's a regular cube?

It's alright.   If you read the Wikipedia page on 3D space, you can see that it only has 3 orthogonal lines.   In fact, it's probably called 3D space for that very reason.

As for your edit, I don't know what you're asking.   There's rectangles inside the cube because there just is.   Take the plane EBCH and it's just a rectangle.   Take a plane through a sphere and you'll get an ellipse.

TrappedTime

Guest

Re: If you like/understand geometry click here

Nevermind, as long as all the edges of the rectangles are equal, it creates a cube.
I got confused

Pike270

Guest

Re: If you like/understand geometry click here

Updated Second Post.

Last edited by Pike270 (Aug 6 2011 6:43:32 pm)

Tako

Member

From: Memphis, Tennessee, USA

Joined: 2015-08-10

Posts: 6,663

Website

Re: If you like/understand geometry click here

Sorry to be off the topic, but Google "four orthogonal lines on a cube".

---

Yeah, well, you know that's just like, uh, your opinion, man.

Pike270

Guest

Re: If you like/understand geometry click here

Think up a transparent cube. Now connect each corner with it's opposite corner to form lines. You get... 4 lines! Now, using some statements about how diagonals in squares are perpendicular, you can use that multiple times to prove all lines are perpendicular.

^ I believe that you are referring to that (orthogonal lines shown in red). Those are orthogonal lines, but in a different context. As shown in the original post, we are talking about perpendicularity.

There are many definitions of "orthogonal": http://dictionary.reference.com/browse/orthogonal

Last edited by Pike270 (Aug 6 2011 10:45:37 pm)