Simulating a Physical Process
When introducing geometry to students in elementary school, some basic geometric facts cannot be presented with formal proofs, but students can be convinced in the validity of these statements through the use of manipulatives or computer simulations.
Example 1. Properties of Parallelograms
This applet simulates the rotation of a parallelogram around the intersection point of its diagonals. It gives an interactive visual proof of basic facts about the sides, angles, and diagonals of parallelograms, rectangles, rhombuses and squares. In addition, by using this applet, the students can improve their understanding of congruent segments and congruent angles.
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Example 2: The Sum of the Interior Angles of a Triangle
This is a common classroom activity for finding the sum of the interior angles in any triangle. The advantage of using a GeoGebra applet over a paper model is in the opportunity to change the shape of the triangle and in a short amount of time see that the property works for all types of triangles. The computer simulation also improves the accuracy of the “folding”.
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