Another Equilateral Comparison

The passing of consecutive isosceles triangle days has me once again thinking about the question “Which Triangle is More Equilateral?”

I first considered the question on 10/10/11, comparing the 10-10-11 triangle and the 10-11-11 triangle.  After a spirited discussion, I offered one approach to the question here.  The problem gave me lots to think about, both mathematically and pedagogically, and I reflected on what I liked about this problem here.

But as 12/11/11 and 12/12/11 pass, I thought I’d revisit my strategy for answering the question “Which triangle is more equilateral?”

My basic strategy, outlined in more detail here, is to ultimately to quantify the circleness of each triangle.  To me, being equilateral is all about trying to be as much like a circle as possible.  So I created a measure to determine how close to circlehood a triangle is.  Here are the numbers.

The 11-12-12 triangle’s measure is closer to 1, thus making it the more equilateral triangle.

Related Posts

 

Math Lesson: European Debt Crisis

My latest contribution to the New York Times Learning Network is a Math Lesson designed around exploring loan repayment and risk assessment in the context of the European Debt Crisis.

https://learning.blogs.nytimes.com/2011/11/30/crunching-the-numbers-exploring-the-math-of-the-debt-crisis/

In this lesson, students interact with some cool infographics, collect debt data, run the numbers on possible loan repayment schedules, and explore an elementary notion of “risk” in finance.

Weavings and Tilings

At the Bridges Math and Art Conference in Portugal I learned quite a bit about mathematics and weaving.  One of the many simple and fun ideas I left with was using weaving to explore tilings of the plane.

With some graph paper to plan your tiling, some pre-cut construction paper to assemble them, and some patience to work through the process, you can produce some nice results.  Here are some examples from a recent Math for America workshop I led on Math and Art.  More images can be seen on my Facebook page.

Geogebra Resources

This is an amazing collection of hundreds (thousands?) of well-designed Geogebra worksheets:

http://dmentrard.free.fr/GEOGEBRA/Maths/accueilmath.htm

The author, Daniel Mentrard, has put together a huge library of mathematics and physics demonstrations/explorations that are all available for free.

Although the site is in French, it’s not too hard to browse the many Geogebra resources covering Arithmetique, Art et Maths, Algebre, and much more.

And if you like, you can always run the website through Google Translate.

2011 Sloan Award Winners

I would like to extend my congratulations to the recipients of the 2011Sloan Awards for Excellence in Teaching Science and Mathematics.

These awards, presented by the Fund for the City of New York, recognize outstanding teachers in the New York City Public School System.  I am very proud to have received this award in 2010.

As a teacher, the current public discourse that focuses mainly on what is “broken” in public education can be deflating.  It is wonderful to be a part of something that honors the great work teachers do every day.

Here’s a short write-up in the New York Times about the winners, and bios and videos of this year’s recipients can be found here:  http://www.fcny.org/fcny/core/sae/.

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