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## Area of Circles

Explore the formula for the area of a circle, by cutting it into sectors and rearranging the sectors to form a figure close to a parallelogram. By increasing the no. of sectors, students observe that the figure tends to a rectangle and get the formula for the area of the circle by finding the area of this rectangle.

Anthony Or. Education Bureau, Hong Kong.
orchiming@gmail.com
（繁體中文版：http://www.geogebratube.org/material/show/id/550
98

Shared by orchiming

Target group (age)
11-14
Language
English (UK)

## Write a comment

• The flip over of the wedges is very nice!
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• Thank you!
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• Excelente recurso.
• Muchas gracias!
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• Superb!
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• Thank you very much!
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• Super! Super! Super! Dla dzieciaków jak znalazł. (For children extra.)
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• Dziękuję bardzo!
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• This is the best way to show other teachers why geogebra is so sweet.
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• Agree! GeoGebra is sweet indeed.
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• Obrigada! É um recurso Fantástico para manipular com alunos!
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•
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• Bom recurso. É pena não ser possível o download, dado nem sempre temos acesso à net
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• The best interactive version of this visual proof I have seen. Thanks very much!
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• Thank you very much!
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• Thank you!
Very good model.
• A circle has zero area, a DISK has an area. Very nicely done.
• Great work!
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• Thank you very much, Valery, Christian and Dev1!
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• Great ! buddy....Thanks!!!
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• You are most welcome!
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• Fantastic! Cheers!!
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• Thanks!
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• Lucid clear and direct. I aspire to this level in my Geogebra work and hopefully will achieve it fairly soon!
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