In this Warm-Up, I ask students to bring back their Algebra 1 solving skills to do some problem problem solving with the area and perimeter of rectangles. I like Problem 1 because it really requires students to spend time deciphering what the problem is asking them to do, which leads to rich discussion and a way to preview ideas about similarity.
I number students off to create six new "expert" groups. I assign each expert group one of the six special quadrilaterals and show a PowerPoint to make my expectations of the group product (two twin posters*) clear. Through their posters, expert groups are to show ALL the properties for their special quadrilateral, as well as a minimal defining list that would guarantee anyone would draw their special quadrilateral only.
*I ask students to make twin posters because I will divide the expert group into two smaller groups (2 or 3 students in each) so that they can present their work in a smaller setting.
After expert groups have made their twin posters, I divide the class into two halves. I do this because at this early point in the year, students need to feel safe when presenting their work to others. I have also found that groups of 12-15 people allows for discussion to occur more naturally than in a whole-class setting, which is important because I want students to make comments and ask questions as the expert groups present (MP3).
Each expert group (2-3 people) presents their poster and takes questions and answers from the audience.
I ask groups to present in the following order (least to greatest number of requirements): kites, trapezoids, parallelograms, rectangle, rhombus, and square. As expert groups present, I walk back and forth between both halves of the classroom, listening in to the presentations so I can highlight key ideas shared in the next lesson when we "clean up" the definition for each special quadrilateral.
After students have given their poster presentations, I want to make sure to wrap up with a whole class discussion where we talk about how the special quadrilaterals are related, yet different from each other. I make sure to ask students if they can explain the particular order of the poster presentations (kite, trapezoid, parallelogram, rectangle, rhombus, square) which gives us an opportunity to talk about classification and differentiation. For example, kites and trapezoids are separate from parallelograms, rectangles, rhombuses, and squares, which have a lot in common.