December 9, 2012

Parallel Lines and Transversals

Each quarter I have my geometry students write a lab report.  First quarter we study lines and angles, so the lab is on parallel lines and transversals.  Second quarter is congruent triangles (coming soon), third quarter is area of quadrilaterals (although I will probably re-write this one yet again) and fourth quarter is aging trees (unit on circles).  I like doing these reports since it formalizes some of the experimentation we do and it involves technical writing, which is what mathematical writing should be.  Plus I love science so I'm happy to support them by having students practice using the same format as the science department does.  To make life easier (for me and my students) I give them a template to fill out which makes it quite clear what the sections are and what information goes into each one.

This lesson was student's first time using GeoGebra this year.  As Kate said, it's just such a hassle to get and set up technology I can't be bothered to use it often.  However, students were going to take a test on the first half of the lines and angles unit, then use the computers.  This was a nice set up; since not every kid got a laptop at the same time I had the freedom to help each student log in and get started.  Staggered start times seems to be a good technique for successful tech integration.

Since it was students' first foray into GeoGebra they had 10 minutes to explore.  Some students didn't want to take the time to explore, which surprised me.  Those same students then asked me where to find the tools, so of course my response was - "Explore! Find them yourself."  If students had taken time to look around and still didn't understand how to use the program I was happy to help troubleshoot, but the directions are sufficiently clear that students who are willing to put in some effort can successfully complete this lab independently.  I only gave them the first two pages of the document below to star and encouraged them to write down as many observations as possible.  Some students tried to skip drawing the second set of angles, and quite a few students had trouble measuring all 8 angles in the diagram (showing them how to move the numbers into a more convenient location is key, otherwise the measurements all pile up and it is confusing).  When students claimed to be done, I gave them the lab report format (pages 3 & 4).  For the regular level class the report was assigned as homework, for the fundamentals level they completed as much as possible for homework, then we shared and filled in the gaps the following class.

Transversal GeoGebra Lab
(This is a pdf, for an editable version you can use this .doc but the formatting isn't exactly right)

I had a student refer back to the first handout just last week (months later) when they needed to review angle pairs even though we took notes and made flappers (scroll down for images and find a description above the photos), so apparently the lab made enough of an impression that it was what they chose to look for as reference.

1. This is great. I like the "lab" idea and corresponding write up. I'm sure its very effective. Do you have students having a hard time working with Geogebra? Or do they pick up on all the details pretty quickly?

1. Thanks! Students who have just a bit of patience do great. The measuring angles tool is a bit tricky since you have to select 3 points moving clockwise (I think) or else you get the angle that's greater than 180 degrees. Which is no big deal if you paid attention and can undo and go in the opposite direction, but impatient kids will just leave the extra measurement and try another angle which can end up with a mess. They also don't all construct parallel lines but instead make them look parallel, however that's a key learning opportunity about what makes lines parallel and a feature of the program rather than a fault.

2. Thank you for sharing this.

3. What a great idea. I love this!! Thank you!!

1. FYI: I continued to do the lab each year but found pencil and paper investigation to be just as effective as geogebra, without the hassle of needing to get the laptop carts and teach kids geogebra. It's a great intro activity if you plan to use geogebra throughout the year though.

4. Thanks for sharing! Did you mean to say LM is perpendicular to NK in your final discussion question? The key says they are parallel but they certainly appear to be perpendicular.

1. Yup I think that's a scribd issue mixing up the symbols somehow? But definitely perpendicular.