After the Do Now, I have a student read the objectives for the day. This section of the lesson may be a review for your students, or it may be introduction to new material. Change the length/depth of this section of the lesson depending on the needs of your students.

I ask students to share out what a prefix is. I am looking for students to tell me that a prefix is a group of letters that is placed at the beginning of a word that has a specific meaning. Many students will be able to share that the prefix “tri” means three. I have my students think-pair-share about words that begin with “tri” and “quad” for 2-3 minutes. Some examples may include triangle, tripod, triathlon, trio, triplet, trilingual, quadrant, quadruplet, and quadruple. See my video on Think Pair Share in my Strategy folder for an explanation.

I want students to make a connection between the prefix of “quad” and the meaning of quadrilateral. My hope is that with knowledge of prefixes, students will have an easier time recalling the meaning of some mathematical terms.

I have students read through the definitions on the Quadrilateral Notes page. Here are some questions I may ask:

How are all the quadrilaterals similar? (By definition they all have 4 sides)
What is the difference between a rectangle and a square? Use the word congruent in your answer.
What is the difference between a parallelogram and a rhombus?
Can you call a rectangle a square? Why or why not?
Can you call a square a rectangle? Why or why not?
Can you call a square a rhombus? Why or why not?
Can you call a rhombus a square? Why or why not?

If students struggle with these questions, have them draw a Venn diagram for each question. Students can then organize the specific similarities and differences of the two shapes. Some students struggle with questions like the last 4 listed. A square can be called a rectangle because it meets the criteria of a rectangle (4 sides, 2 sets of parallel sides, and 4 right angles). It is important that students understand that although a square can be called a rectangle, the best and most specific name for the quadrilateral is a square. A rectangle cannot be called a square because it does not have 4 congruent sides.

It is important to me that students use the Mathematical Practice 6: Attend to precision with their language throughout this lesson. Students need to be using specific mathematical terms to describe the characteristics of quadrilaterals and how they compare to other quadrilaterals. I push students to use terms like: angles, parallel, and congruent.

I pass out the Naming Quadrilateral reference sheet. We fill in the missing descriptions on the back. I go over how to use the series of questions to identify the first quadrilateral on the Practice page as an example. I walk around to make sure students are writing the specific characteristics of the rhombus under “How do you know?”

I give students 3-5 minutes to classify and write their answers. I walk around and monitor student progress. Some students may struggle with number 2 and 4 if they compare the side lengths visually. I have rulers available if students want to use them to compare side lengths.

When most students are finished we quickly review a couple of the examples and reasoning behind the answers.