Teaching Constructions

When I started my teaching career, I taught the constructions that were required on the state exams by providing my students with an overview of the conventional steps.  I soon learned my approach was completely ineffective. No matter how I varied my instructions, many students perceived constructions as little more than "pictures" that needed to be memorized. 

In my fourth year of teaching, I completely abandoned my traditional method. On the first day of the constructions unit, I have students take out their compasses and given them one goal and a few rules:

The Goal: Use only the compass and ruler to make a diagram full of circles and line segments, according to the rules:

  1. You may start with two points.
  2. Every circle must be centered on an existing point or intersection and must pass through an existing point or intersection.
  3. Every segment must pass through at least two existing intersections or points.
  4. BONUS: See if you can identify any cool patterns or relationships!

While students work, I only walk around to check that students follow the rules. Of course, they quickly identify perpendicular lines, equilateral triangles, parallel lines and more. Using this approach, I never have to teach procedures. If students need to know how to construct perpendicular lines, I ask "do you remember how you figured it out?" and if thy say "no" I say, "I guess you will have to figure it out all over again. Don't forget to follow the rules."

Below, I will add a few of my own assignments. I will update this page periodically, play check back or, if you have any requests or questions, leave a comment!


Constructions Group Quiz (PDF) (DOCX)

This is not just any quiz. If you hav not done a group quiz before, check out this blog entry.