Exploring Shapes

This fall we have been looking at shapes in math group. First we looked at some different triangles and worked to come up with a way to describe a triangle that made it clear what a triangle is. I talked about this as a definition of a triangle. Working in pairs (generated by pulling colored cubes from a box), students shared ideas of what they noticed about the triangles. Then those pairs shared with the others what they came up with. Everyone had noticed the three sides right away. We talked about the difference between an open and closed shape. Several students mentioned the three corners. I introduced the term angle. Then we looked at the word “triangle” and broke it down to tri and angle. One student quickly made the connection to tricycle. That same day we looked at squares and talked a little about how we could describe them.

A few weeks later we revisited the square discussion. This time I drew a square on the board along with some other quadrilaterals. I asked them to work independently this time to describe what a square is in their journals. It was interesting to see how closely some observed the shapes and used terms that sounded more mathematical while others used more visual terms. For example in trying to distinguish a square from a parallelogram with equal sides, several students wrote that a square is not “squished.” Others said the square did not have diagonal lines as a way to describe the same attribute.

The next time we met we shared our ideas. We revisited the idea of angles. At that point one student made the connection to Logo programming which he had heard about from his older brother. We then explored the idea of different sized angles. Some students were recognizing the distinct angle in a square, so I introduced the term “right angle.”