Women specific geometry

20 August , 2010

They have their own geometry? I really wasn’t aware…


Morley’s theorem

4 June , 2010

I am still not able to post GeoGebra-files directly on WordPress, so I will stick to linking to my Norwegian blog. Last dynamic geometric gem is the theorem of Morley, stating that trisecting angles in a random triangle will give intersection points that are nodes in an equilateral triangle.

Check it out: http://mattegreier.blogspot.com/2010/06/morleys-hjerte.html

Embedding GeoGebra…

25 May , 2009

On my Norwegian mathematics blog, (on Blogspot.com) it was quite easy to embed a Java powered file made in GeoGebra by using GeoGebra’s built in “hosted Java archive” and the GeoGebra Upload Manager. However, I still can’t see how this can be done on WordPress, although I am sure it can! On blogspot, it looks like this: http://mattegreier.blogspot.com/2009/05/aritmetisk-middelverdi.html
Anyone with any further ideas on how to accomplish this on WordPress?

Beer Geometry – CollegeHumor Video

7 March , 2009

Kind of funny – I guess this merges the need for weekend and the work with mathematics…


Pedagoguery Software: Poly

21 January , 2009

A great little freeware to show off today! As a mathematics teacher, and frequent user of whiteboards/smartboards, I am always

looking for nice programs or web sites to use interactively. This is one particularily good program that does just one thing, but does it good. It shows you the most common and a lot of the uncommon geometric solids. You can (use your hands on the smartboard to) zoom in and out on the solids, open them up and crunch them back together again. You can print the layout nets for each solid if you want to make your own physical model. For instance, have your students make footballs (I am talking soccer, not the “other sort” of football, where they mostly cheat by using their hands) from pentagons and hexgons. Solids can be shown transparent or…well..solid.

Go download a free version at http://www.peda.com/poly/


1 July , 2008

GeoGebra Logo

This computer program has now become extremely popular in Europe. This software package makes it easy to draw geometrical shapes (in 2D) and stretch and turn them around afterwards. That is, it’s a DGS (Dynamic geometry system/software). If you have tried Cabri, you should be no stranger to this.

In addition, you get a function drawing program, were you equally easy can draw most function you will ever need (in 2D). This is all done in the same coordinate system, making it easier to see connections between functions and geometry.

You can also do calculations of many sorts in this software. You can calculate with variables like line segments and function values, and they are (of course) automatically altered and updated when you change your drawing or graphs. You can’t do CAS calculations though.

I have tried a few softwares like this earlier, like Cabri and the newer stuff from Texas Instruments, but nothing comes close to GeoGebra in terms of ease and usability.

You can make dynamic documents and send them off to students. You can use a web version or software version of the program and they are completely identical. You can save stuff as pictures, documents or java applets, and embed them in your website, blog or LMS. What’s not to like?

The software is originally made (I think) as a Ph.D. project in Austria by Markus Hohenwarter. And best of all – it’s completely free and lots of resources exist in all kinds of school levels.

I have held a couple of courses, lectures and workshops around the country, where we have started using this program among others. So far I have been to Molde, Kristiansand S, Oslo, Bergen, Stavanger and Levanger. There’s a bunch of exercises and activities at this site, but the little text there is, is in Norwegian.

I will also give a talk at a conference at NTNU in september where I will talk about a practical pedagogy for GeoGebra. My intentions are to focus on the gap between the teacher and learner, and we go about forcing ourselves to take the learner aspect into our lesson planning.