Attributes of Quadrilaterals

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Objective

SWBAT identify properties of quadrilaterals

Big Idea

Students review vocabulary associated with quadrilaterals and create a graphic organizer showing the properties of quadrilaterals.

Do Now

10 minutes

As students walk in the room, they are given a small sheet of paper with ten statements on it. They are instructed to write "all," "some," or "no" next to the statement to make it true. Students build on the activity from the previous lesson to answer the questions. 

After about 4 minutes, we go over the answers as a class. I call on a random student to read the statement with his or her response. For example, "All squares are rhombi." We often get into a discussion about the pairs of statements that have the same shapes in a different order. It is difficult for some students to understand that all squares are rhombi, but not all rhombi are squares. 

When we come across a statement that has an answer of "some," we identify when the first shape can be called the second shape. For the statement, "Some trapezoids are isosceles," we add "when they have two congruent sides."

Teacher's Note: Students often ask what a "rhombi" is. I tell them this is the plural of rhombus. It is also possible to "rhombuses" as the plural of rhombus. Mathematicians have not decided on the word for more than one rhombus.

 

Mini-Lesson

10 minutes

In the Mini-Lesson, my students create a diagram showing the properties of specific quadrilaterals. They draw pictures of the quadrilateral and label its properties. My students may need to be reminded of the symbols used to label congruent and parallel parts. The diagram is organized hierarchically, so each shape has all of the properties of the shape above it. 

Students begin the Mini-Lesson by drawing any quadrilateral. They then draw a parallelogram. Since they use graph paper, it is easy to draw an accurate parallelogram with a ruler. After the students draw the parallelogram, we discuss properties that can be identified from the drawing. The process is repeated with the other shapes, rectangle, rhombus, square, trapezoid, isosceles trapezoid and kite.

Although the diagram does not show the properties of the diagonals of each quadrilateral, we will cover these as well. After reviewing the basic properties, we will add the diagonals to the diagrams. Then, we will discuss these properties as well. 

Activity

15 minutes

After the students have completed their chart, I have them work individually to write out the properties for each shape in their notebooks. In order to do this, they must be able to understand the labels on the shapes from their diagrams. I instruct the students to write all of the properties for each shape. When they refer back to their notes in later lessons, all of the information will be in one place, which makes it easier for them to find. These notes are useful when addressing standard G.CO.11 "Prove theorems about parallelograms."

After about ten minutes, the students share their notes with the person next to them to ensure they have all of the properties written for each shape. If they are missing any properties, they can add to their notes. 

As an alternative, I assign groups of students a specific quadrilateral and give out chart paper to write the properties on. They write the name of the quadrilateral, draw a picture, and list the properties. At the end of the activity, each group presents their chart to the rest of the class. Each student can copy the information from the chart.

Summary

10 minutes

At the end of the lesson, the students take a quiz. On the quiz, there are pictures of specific quadrilaterals with a list of properties below them. The students have to identify which properties pertain to the named quadrilateral. 

For later lessons in the unit, students need to be familiar with the properties of quadrilaterals. This quiz assesses how well the students are able to identify the properties of quadrilaterals at this point and helps inform future instruction.