Here’s something cool that you can do with your students to help them develop and use the vocabulary of geometry, as well as refine their observation and reasoning skills. It also gets your students to think about what are “good” questions to when classifying a shape, and then how to follow those questions with more questions.
The game itself is simple: print up the shape cards, cut them out and tape them onto students’ backs. The students then walk around the room asking “yes/no” questions about the properties of those shapes, until they reach a conclusion of what the name of the shape is and make a sketch of what they think it could be.
As usual when it comes to these types of things, I’ll leave some of the specifics for you to figure out the implementation. The way I developed it was to give small groups of students a full set of cards so they knew what types of shapes might be on their backs. They work together to develop yes/no questions that would narrow down what the shape could be based on its properties.
I usually have my students work in groups to write down the questions, collect them, type up their questions (omitting duplicates and refining those that have grammatical or spelling errors), print out the list, and let the students pick out ten of the questions and writing them down on the Guess It! answer sheet. I also leave 3 spaces blank so that students can write in their own questions “one the spot,” because sometimes they need additional information to help figure out the type of shape.
I’ve also included a list of sample questions that your students may want to use. You’ll notice that there is a column on the answer sheets called “order.” This is to help your students record when they asked the question, which recognizes that some questions may not longer be valid and can be omitted from their list. For example, if it is determined that the shape is a triangle, then the student can skip questions about parallel sides, opposite sides, etc. and go right to questions about the types of angles and the length of the sides.
I’ve also included a Guess It! “flow chart” where students can record the flow of the logic that leads them to an answer. The goal here is to help students understand there is a chain of logic that starts from the most general (“is it a quadrilateral?”), becoming more and more specific (“does it have 2 legs that are equal?”) until the student reaches the conclusion that it is an isosceles trapezoid.
I made a set of cards that includes three dimensional shapes as well. You may want to use these as, but if that’s not in your curriculum, it’s cool, just don’t use them. I also left you a blank page where you can also draw in your own shapes, although I’m not sure what I may have left out (unless you’re teaching about hypercubes, Klein bottles and tori as well.....)
One of the feature’s you’ll notice is that I did not make “prototypical” examples of the different shapes. For example, I tilted the square so that students understand that even though it is not oriented on its side, it’s still a square (and not a diamond.) The same is true of shapes like trapezoids where I intentially oriented the “bases” on the right and left side, so that they would understand that since there is exactly one set of parallel lines, it is a trapezoid.
Let’s face it, textbooks do a terrible job showing examples of geometric shapes, to the point that our students don’t recognize common shapes simply because they are not shown in “prototypical” ways. This is especially important preparation for high school geometry, when students have to look at complex diagrams where shapes are parts of other shapes and may not always be oriented in standard ways.