Making line designs is an excellent extended project for a 4th or 5th grade class. It integrates many skills and concepts, and students get to take something home they can display. A class can complete a line design, starting with an 11” square with only a large circle with the center marked on it, in […]

## Measuring angles as parts of circles

When we first introduce angles, we can immediately draw the connection between angles and circles. This is a rich and interesting relationship, and because we are drawing circles and angles, and measuring them numerically at the same time, we can clearly see the relationship between the numbers and the drawings. The following is taken from […]

## Classifying quadrilaterals with The Parallelogram Machine

The Parallelogram Machine is meant to illustrate why rectangles are also parallelograms. I have an activity entitled Quadrilateral Sorting, or How can a square be a Rectangle? that uses 3 models of these. As you can see, the machine makes only parallelograms. How does that work? Well, the opposite sides are equal. In the drawing above, […]