### Categories

### Recent Comments

- tpc on Mathematics and poetry
- tpc on Discovery
- tpc on Dear Maurits
- Twin corrections | eon on Mathematics and Coffee
- tpc on Prime (Car) Number

### Links

### Archives

- December 2017
- November 2017
- August 2017
- May 2017
- April 2017
- March 2017
- October 2016
- September 2016
- August 2016
- July 2016
- December 2015
- October 2015
- September 2015
- August 2015
- June 2015
- March 2015
- February 2015
- January 2015
- August 2014
- July 2014
- June 2014
- April 2014
- March 2014
- January 2014
- November 2013
- October 2013
- September 2013
- August 2013
- July 2013
- June 2013
- May 2013
- April 2013
- February 2013
- January 2013
- December 2012
- November 2012
- October 2012
- September 2012
- August 2012
- July 2012
- June 2012
- May 2012
- March 2012
- February 2012
- January 2012
- December 2011
- November 2011
- October 2011
- September 2011
- August 2011
- July 2011
- June 2011
- May 2011
- April 2011
- March 2011
- February 2011
- January 2011
- December 2010
- November 2010
- October 2010
- September 2010
- August 2010
- July 2010
- June 2010
- May 2010
- April 2010
- March 2010
- February 2010
- January 2010
- October 2009
- September 2009
- August 2009
- July 2009
- June 2009
- May 2009
- April 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
- June 2008
- May 2008
- April 2008
- March 2008
- January 2008
- December 2007
- November 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- March 2007
- February 2007
- January 2007
- December 2006
- November 2006
- October 2006
- September 2006
- August 2006
- July 2006
- June 2006
- May 2006
- April 2006
- March 2006
- February 2006
- January 2006
- December 2005
- November 2005
- September 2005
- August 2005
- July 2005
- June 2005
- May 2005
- April 2005
- March 2005
- February 2005
- January 2005
- December 2004
- November 2004

### Meta

# Category Archives: Geometry/Topology

## One-seventh ellipse

Fun fact. It is well known that [tex] \frac{1}{7} = 0.\overline{142857} [/tex]. It turns out that if the repeating digits are taken in sequence as (x,y) pairs in the following manner to form six points: (1,4), (4,2), (2,8), (8,5), (5,7), … Continue reading

Posted in Fun Stuff, Geometry/Topology
Leave a comment

## Notes from ICME13

Gila Hanna mentioned the carpet proof of the irrationality of [tex]\sqrt{2}[/tex]. A little digging reveals that it was due to Tennenbaum (1950s) and popularized by Conway (1990s). The original proof appeared in a book but the simple idea is described … Continue reading

Posted in Geometry/Topology, Number Theory, Quotes/People
Leave a comment

## A Sunday Morning Geometry Problem

It’s 6.15 am on a Sunday morning, 18th October to be exact. The newspapers have not been delivered and the kids are still sleeping. Some peace and quiet for me to do some reading while sipping my morning coffee … … Continue reading

Posted in Fun Stuff, Geometry/Topology, Problems
Leave a comment

## Kobon Triangles

Students occasionally have great ideas. Was discussing a problem that originated from some students but was not very well posed. We managed to reformulate it as the maximum number of triangles that can be formed with n lines. This turns … Continue reading

Posted in Geometry/Topology, Problems
Leave a comment

## Come Together

is not the beatles song but the title of episode 16 of a tv program called discover science. I happened to catch it on local tv and the combination of quirky Japanese humour and the clever introduction to mathematics and … Continue reading

Posted in Geometry/Topology, Science, Teaching
Leave a comment

## Maths & Fashion

That headline caught my eye and earned the newspaper article a more detailed look. It’s about a sub brand from Issey Miyake called 132.5, which apparently stands for 1 piece of material which forms a 3d dress but yet can … Continue reading

Posted in Fun Stuff, Geometry/Topology
Leave a comment

## The broken stick problem

A slick solution to the broken stick problem or otherwise known as the uncooked spaghetti problem

Posted in Geometry/Topology, Probability, Problems
Leave a comment

## Polynomial Puzzle and Lill’s Method

I have in mind a polynomial with nonnegative integer coefficients. Can you determine completely the polynomial by just asking two questions? I forgot where I saw this from but it was interesting enough to spur a few lunch time discussions … Continue reading

Posted in Algebra, Geometry/Topology, Problems
Leave a comment

## Can computers write proofs

that human being can understand? By that I mean not those formal logic nonsense. Tim Gowers is doing an interesting experiment to get readers to judge proofs of exercises in metric space theory. The three proofs are supposed to be … Continue reading

Posted in Geometry/Topology, Problems, Technology
Leave a comment

## Geometry Puzzle

A neat little puzzle from John Mason. How are the blue and red area related?

Posted in Geometry/Topology, Problems
Leave a comment

## Nice geometry problem

From the MAA minute math! a problem on 3d geometry. I must confess I peeped at the hint.

Posted in Geometry/Topology, Problems
Leave a comment

## Dodecagon

Funny cartoon from savage chickens.link

Posted in Fun Stuff, Geometry/Topology
Leave a comment

## A matter of perspective

Have you ever watched rugby matches on TV and noticed the advertisements on the field that looked 3-dimensional? I remember having the impression that the adverts were superimposed by the TV people. But when I told the wife, she plainly … Continue reading

Posted in Applications, Books, Geometry/Topology
1 Comment

## Soap bubbles and current research

That’s the title of Frank Morgan’s talk today. The main takeaway is how, (motivated?) students can be exposed to interesting problems and work on current research. For example, it has been known for almost 2000 years that the circle in … Continue reading

Posted in Fun Stuff, Geometry/Topology, Teaching
Leave a comment

## MAA and applications of topology

I used to be a member of MAA but found that it did nothing much for me except I get to issues of American Mathematical Monthly. I would classify that as good to have – something to read when I … Continue reading

Posted in Applications, Geometry/Topology
Leave a comment

## Origami and Mathematics

Recently I had the horrendous realization that I’ve lost whatever little origami skills that I once possessed. I was trying to entertain a bored child on the plane who speaks a little English, and I knew no German save “guten … Continue reading

Posted in Applications, Fun Stuff, Geometry/Topology, Technology
Leave a comment

## Picture Hanging Puzzle

Just attended a nice talk by Erik Demaine on Origami and puzzles. He demonstrated some remarkable stuff and ended with a cute picture hanging puzzle – how to hang a puzzle with two nails such that by removing either one, … Continue reading

Posted in Fun Stuff, Geometry/Topology
1 Comment

## How Did Escher Do It

I’ve always loved Escher’s circle limit. Here’s a neat article attempting to reconstruct it.

Posted in Geometry/Topology, Quotes/People
Leave a comment

## Klein Bottle Opener

How cool is that! http://www.bathsheba.com/math/klein/klein_x1.html $78 though.

Posted in Fun Stuff, Geometry/Topology
Leave a comment

## Finite Projective Plane

Learned a cool trick today. The finite projective plane of order n has [tex]n^2 + n + 1[/tex] points, [tex]n^2 + n + 1[/tex] lines, [tex]n + 1[/tex] points on each line, [tex]n + 1[/tex] lines passing each point. The … Continue reading

Posted in Combinatorics, Geometry/Topology
Leave a comment