Activity Overview
Students draw trapezoids and investigate their properties. They derive the area formula for a triangle from the area formula for a trapezoid. They also investigate the terms: Isosceles trapezoid and Tessellation.
Before the Activity
See the attached PDF file for detailed instructions for this activity
Print page 5 from the attached PDF file for your class
During the Activity
Distribute the page to the class.
Follow the Activity procedures:
Determine 3 ways to draw a trapezoid and drag independent points to ensure that the figure remains a trapezoid
Note that the sum of all interior angles is 360 degrees
Find a relationship regarding angle measurement that appears to be true
Drag the vertex and observe the relationship
Determine 3 ways to construct an isosceles trapezoid
Find at least 3 properties that are true for all isosceles trapezoids
Drag a vertex along the shorter base till its length becomes zero and the trapezoid becomes a triangle
Explore how the area of the trapezoid can be used to find the area of the triangle
Find the relationship between midsegment of a trapezoid and a triangle
Use the Transformation tool to tesselate a trapezoid and observe the figure formed
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary