Experiment: Properties of Trapezoids

Objective

This experiment is designed to provide an interactive environment in which students can discover and investigate the important properties of trapezoids.

User´s Guide

By dragging any of the vertices of the trapezoid, students can change the shape or the size:

  1. Drag any of the four vertices horizontally to change the angles between the two nonparallel sides and the two bases.
  2. Drag any of the four vertices vertically to change the altitude.
  3. Drag any of the vertices diagonally to scale the trapezoid in both horizontal (the related base) and vertical directions.
  4. In addition, each of the slider bars can be used to scale the trapezoid horizontally or vertically.
  5. The display of diagonals, angles, and related numerical information can be turned on and off as desired.

Since this program can generate an unlimited number of trapezoids, it will provide students with a convenient environment to discover and observe common properties among all trapezoids.

 
 
 
 
Experiment: Properties of Trapezoids
Suggested Experiments

  1. What do you notice about the sum of each pair of consecutive angles that are between the bases of the newly formed trapezoid?
  2. Adjust the two nonparallel sides to make them equal to obtain an isosceles trapezoid. Are the base angles of an isosceles trapezoid equal?
  3. Are the two diagonals of an isosceles trapezoid equal? Do they bisect each other?