Conservation of Area
Introduction
Which do you think bigger, the area of rectangle ABCD and parallelogram ABEF?
What is your reason? How do you explain your idea to your friends?
One of my student did not believe that the area of a parallelogram is
always the same if the base and the height are equal. How dou you
explain your idea to him. The applet below gives one explanation to our
question.
How to use the applet.
To shift the figure, press "Left" and "Right" button.
You can also move each rectangle to left and right by dragging it.
The total area of the figure does not change since the area of
the every narrow rectangle is always the same.
The Applet
The Real Model
The photo below is a gage to record shapes. It consists of many slidable
thin plates.
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