Visually Introducing a Trapezoid/Trapezium
In this activity, you will be visually introduced to a trapezium (trapezoid), and by dragging visually explore its special cases in relation to other quadrilaterals, and eventually classify them in the form of a 'family tree'.
Trapezoid/Trapezium
Note: The intention of the suggested dynamic activities above is not to replace traditional geometric manipulatives such as cardboard, paper, geoboard or plastic representations of various quadrilaterals, but rather to supplement and compliment those hands-on concrete activities.
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Related Links
Visually Introducing & Classifying Quadrilaterals
Introducing, Classifying, Exploring, Constructing & Defining Quadrilaterals
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Definitions and some Properties of Quadrilaterals
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Clough's Theorem (a variation of Viviani) and some Generalizations
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SA Mathematics Olympiad 2022, Round 2, Q25
An extension of the IMO 2014 Problem 4
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A 1999 British Mathematics Olympiad Problem and its dual
Dirk Laurie Tribute Problem
Golden Quadrilaterals
Crossed Quadrilateral Properties
Finding the Area of a Crossed Quadrilateral
Extangential Quadrilateral
Triangulated Tangential Hexagon theorem
Theorem of Gusić & Mladinić
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A Quarter Circle Investigation, Explanation & Generalization
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Free Download of Geometer's Sketchpad
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Created by Michael de Villiers in 13 July 2008; converted to WebSketchpad, 1 March 2025.