The purpose of this lesson is for students to explore two different definitions of trapezoid.
The purpose of this lesson is for students to explore trapezoids and agree on a definition of trapezoids for this course. In the first activity, students see two different definitions for a trapezoid both of which are commonly used, one that excludes parallelograms and one that includes parallelograms. The exclusive definition of a trapezoid states that a trapezoid has exactly one pair of opposite sides that are parallel. The inclusive definition states that a trapezoid has at least one pair of opposite sides that are parallel. In the second activity, students recognize that we have chosen to use the inclusive definition of a trapezoid. Students should have access to straight edges, protractors, and patty paper throughout this lesson.
Activity 1: What’s a Trapezoid?
- Compare different definitions for trapezoids, and use them to identify trapezoids.
- Let’s explore trapezoids.
|Activity 1||20 min|
|Activity 2||15 min|
|Lesson Synthesis||10 min|
Teacher Reflection Questions
Did students notice the difference in the definitions of the trapezoid? How did they explain that difference in terms of the hierarchy on the anchor chart?
- Can You Draw It? (1–5), Stage 6: Shapes on the Coordinate Grid (Addressing)
- Which One? (K–5), Stage 6: Shapes on the Coordinate Grid (Addressing)
- How Are They the Same? (1–5), Stage 4: Grade 4 Shapes (Supporting)
Print Formatted Materials
For access, consult one of our IM Certified Partners.