To assess prior knowledge, view the
KWL Chart from the previous lesson and ask students what amendments they would make to the chart today based upon yesterday’s lesson. This will give you a quick assessment of what students learned from the previous lesson and what you need to review before continuing with this lesson.
Alternatively, or as a lesson pre-assessment, students can work (either individually or in pairs) to review the basic geometric shapes (explored in this lesson) by using the Concentration activity.
To do so, students should select the shapes under Levels, and either 1 or 2 players. In this activity, students match the names of common geometric shapes with picture representations.
The lesson then continues as described below.
On the Virtual Geoboard E-Example, have students create three-sided figures and compare them with those of a neighbor. Ask students to discuss the similarities and differences among the figures.
As a class, discuss the properties common to each figure. Encourage students to make connections among learning experiences to confirm their understanding of the properties of geometric shapes.
Students should work in pairs for this lesson. Have students create a four-sided figure and compare it with the one their partner made. Ask students to discuss the similarities and differences among the figures. As a class, discuss the properties common to each figure. Each figure has four sides.
Explain to students that they will experiment with other geometric properties important to understanding and working with figures. Also explain that you will give them time at the end of the lesson to explore other ideas they may have.
Tell students to use two rubber bands on the Virtual Geoboard E-Example to make a set of parallel line segments. As students work, pose the following questions.
- What is the important property of parallel lines? [They are two lines and they never touch.]
- How are parallel lines used in the environment and in art? [Examples might include railroad tracks, lines on a road, the sides of a bridge.]
Next, ask students to use two rubber bands on the Virtual Geoboard E-Example to make intersecting lines.
As students work, monitor their progress to check for understanding. Note which students demonstrate a complete level of understanding and those that need additional instruction and practice with the concepts of this lesson. The following questions will guide student’s attention to the similarities and differences between parallel and intersecting lines.
- What happens to the two intersecting lines? [They are touching each other (they meet.)]
- How do intersecting lines compare with parallel lines?
Have students use two rubber bands on the Virtual Geoboard E-Example to make perpendicular lines. Ask them to show a neighbor their example. Ask the following questions to direct students’ attention to the properties of perpendicular lines.
- What is special about perpendicular lines? [Perpendicular lines intersect to make a right angle (of 90 degrees.)]
- How are perpendicular lines and parallel lines different?
- Why is it important to know the properties of perpendicular and parallel lines as related to the previous lesson?
Tell students to make a quadrilateral with one set of parallel lines, two acute angles, and two obtuse angles. By asking the following questions, you can direct students’ attention to the properties of trapezoids. (Note: This is only one type of trapezoid.)
- What is name of your figure? [trapezoid]
- How do trapezoids differ from other quadrilaterals?
- Describe the properties of a trapezoid.
Ask students to make a quadrilateral that has two sets of parallel lines. Use the following questions to guide the discussion:
- What is the name of your shape? [parallelogram]
- Why is it important to know the properties of these figures compared with the figures in the previous lesson? [Not all quadrilaterals are rectangles.]
- Describe the properties of a parallelogram and explain how it differs from other quadrilaterals.
Have students make a shape that has five sides. Pose the following questions to help students see relationships between sides and angles.
- What is the name of this figure? [pentagon]
- How many vertices does it have? [5]
- How does it compare with other figures we have made?
- Why is it important to know the properties of these figures compared with the figures studied previously?
Repeat with figures of six and eight sides. Ask the following questions to focus students’ attention on the properties of hexagons and octagons compared with other polygons.
- What is the name of this figure? [hexagon or octagon]
- How many vertices does it have? [6 or 8]
- How does it compare with other figures we have made?
- Why is it important to know the properties of these figures compared with the figures studied previously?
Have one student volunteer to make each of the figures created in this lesson on the geoboard. Then have the student stand before the class so that others can visually compare the various shapes.
Invite students to discuss the similarities and differences. Focus attention on the discussion of parallel lines, perpendicular lines, and intersecting lines. Discuss the derivation of the names for each of the polygons.
To bring closure to the lesson, have students pair with a partner and take turns making shapes. Have the partner identify the vertices, numbers of sides, types of lines (parallel, perpendicular, intersecting), and angles.
