[math-fun] A=bh/2
Remember when they taught you that the area of a triangle is half the area of the parallelogram you get by gluing two copies together? And the area of the parallelogram is the area of the rectangle you get by chopping a triangle off one end and gluing it on the other? Did anybody complain that this doesn't work for sufficiently skewed parallelograms? Fix: gosper.org/A=f(bh).gif --rwg
Minor point: The URL has to be copied and pasted since it didn't all make it into the linky stuff. Also, I think this might make the point more clearly if it began with a picture of the unduly skewly paralleluly. —Dan
On Feb 14, 2016, at 1:33 PM, Bill Gosper <billgosper@gmail.com> wrote:
Remember when they taught you that the area of a triangle is half the area of the parallelogram you get by gluing two copies together? And the area of the parallelogram is the area of the rectangle you get by chopping a triangle off one end and gluing it on the other? Did anybody complain that this doesn't work for sufficiently skewed parallelograms? Fix: gosper.org/A=f <http://gosper.org/A=f>(bh).gif --rwg
On Sun, Feb 14, 2016 at 2:43 PM, Dan Asimov <asimov@msri.org> wrote:
Minor point: The URL has to be copied and pasted since it didn't all make it into the linky stuff.
I think that's an effect of your mail client, Dan. Bill's original doesn't have the link in it, and GMail "linkified" it fine for me. -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
Yes — weird. I looked at the original e-mail and as you say the link appears fine. But in my catchall inbox, the copy or alias of that e-mail has the URL chopped up infelicitously. The culprit is the Mac Mail program, which is extremely buggy. —Dan
On Feb 14, 2016, at 3:09 PM, Mike Stay <metaweta@gmail.com> wrote:
On Sun, Feb 14, 2016 at 2:43 PM, Dan Asimov <asimov@msri.org> wrote:
Minor point: The URL has to be copied and pasted since it didn't all make it into the linky stuff.
I think that's an effect of your mail client, Dan. Bill's original doesn't have the link in it, and GMail "linkified" it fine for me.
Bill, I didn't see at all how the animated picture illustrated your post. It would be much more clear if you could present a fixed picture of the parallelogram with a line bisecting it into the two triangles, and a picture of a parallelogram with a line indicating the triangle to be chopped off. -- Gene From: Bill Gosper <billgosper@gmail.com> To: math-fun@mailman.xmission.com Sent: Sunday, February 14, 2016 1:33 PM Subject: [math-fun] A=bh/2 Remember when they taught you that the area of a triangle is half the area of the parallelogram you get by gluing two copies together? And the area of the parallelogram is the area of the rectangle you get by chopping a triangle off one end and gluing it on the other? Did anybody complain that this doesn't work for sufficiently skewed parallelograms? Fix: gosper.org/A=f(bh).gif --rwg _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (5)
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Bill Gosper -
Dan Asimov -
Dan Asimov -
Eugene Salamin -
Mike Stay