kitchen table math, the sequel: Proofs without Words

Wednesday, August 4, 2010

Daniel Ethier said...: I think this is an interesting book. It uses visuals to prove various things, in algebra, geometry, trig, etc. There is a nice visual proof of why the geometric mean is less than the arithmetic mean, for example.; August 4, 2010 at 8:06 PM
Barry Garelick said...: I looked at the proofs for Pythagorean theorem. Not obvious to me how the various dissections works, and I doubt that students will figure them out either. The dissections are nice, but you do need statements and reasons to justify the various things going on.; August 5, 2010 at 6:16 AM
Anonymous said...: i love this stuff.
haven't seen the book but
many of 'em will presumably
have appeared in MAA's
_american_mathematical_monthly_
(which i used to see regularly).

i've been doing "lectures without
words" in zine form (and distributing
them in the low dozens) for, what,
the better part of a year or so.

the "dissection" here
(early on, in black-and-white),
for me, qualifies as "without words"
(and as a "proof from the book"
per pal erdos). my first exposure
to proof-by-dissection, though,
was the far-less-obvious BEHOLD
proof attributed to bhaskara.
i saw it in the justly-famous
dolciani series of highschool texts.

owen thomas; August 5, 2010 at 12:24 PM

kitchen table math, the sequel