Lesson 5 Trapezoids

    • Let’s explore trapezoids.

Warm-up What Do You Know About …?

What do you know about trapezoids?

Activity 1 What’s a Trapezoid?

  1. Draw a trapezoid. Label the coordinates of the grid points you used.

    Coordinate grid. horizontal and vertical axis, 0 to 10, by 1's.

  2. Is it a square? Rectangle? Rhombus? Parallelogram? Explain your reasoning.

  3. Describe a trapezoid in your own words. Compare your definition with a partner.

  4. Is this shape a trapezoid according to your definition? Explain your reasoning.

    Quadrilateral. 2 sets of parallel sides. 

Activity 2 Two Definitions of a Trapezoid

Problem 1

venn diagram. set labeled trapezoids. set labeled parallelograms. No overlap. 
Venn diagram. set labeled parallelograms contained in set labeled trapezoids. 

Problem 2

Definition 1

Definition 2

A trapezoid has exactly one pair of opposite sides that are parallel.

A trapezoid has at least one pair of opposite sides that are parallel.

Which statements go with the first definition? Which statements go with the second definition? Explain or show your reasoning.

  1. All parallelograms are trapezoids.

  2. No parallelograms are trapezoids.

  3. All trapezoids are parallelograms.

  4. Some trapezoids are parallelograms.

  5. No trapezoids are parallelograms.

Practice Problem

Problem 1

  1. Draw a trapezoid that is also a parallelogram. Explain how you know it is a trapezoid and a parallelogram.

    blank grid

  2. Draw a trapezoid that is not a parallelogram. Explain how you know it is a trapezoid but is not a parallelogram.

    blank grid