A new page for your enjoyment: Parallel and Perpendicular Lines and Planes

Comments, suggestions welcome.

Click onto this link for the problem (mind bender) at the bottom of the page.

http://www.mathsisfun.com/perpendicular-parallel.html

"Mind Bender

Something that makes my mind bend: we know that if we have two parallel lines,

and we rotate one by 90°, they will be perpendicular to each other, right?

Well, does the same apply to curves? Can you have "perpendicular curves",

by rotating one of them by 90°? I simply don't know, but it is fun to think about."

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Let there be two racetrack-shaped closed curves,

not necessarily the same width or length, having

semicircles at each end facing out and each semicircle

is connected by parallel lines to the endpoints of the

respective semicircles.

Let these two curves be oriented parallel to each other,

have sufficiently long line segment sides to connect

the semicircles, and be positioned relative to each other

so that when one is rotated 90 degrees, there will be

either two intersection points or four intersections where

the intersecting sides will be perpendicular to each other.

Before the rotation of 90 degrees, there are cases where

one of these "racetrack" curves might even be completely

inside of the other.

EDIT: what i like very much is that you mention that how we draw the line is just our illustration,which is not mentioned that often in other places!

]]>nice explanation,definitely easier to understand!

I just have to ask which grade is this meant for?

]]>(PS: I never answered your question, sorry. I used Blu-Tack)

]]>With my gravity field generator ... doesn't everyone have one?

Sadly not. Now that would have been very handy for moving the shed. As it was we had to resort to very old technology ... Egyptian I think ... we used rollers.

Bob

]]>The page is well made. The illustration is neat! Thanks!

]]>How did you get that pencil to stay at an angle to your table?

With my gravity field generator ... doesn't everyone have one?

]]>That's a good page you've got there. How did you get that pencil to stay at an angle to your table?

Bob

]]>Very good!

]]>Comments, suggestions welcome.

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