Outline: "constructing three-dimensional figures by rotating plane figures."
... Learning activities
...Teacher's instructions/guide 
... Evaluation (expected student responses)
Regarding the necessary software data for using "Cabri 3D File" and "Flash Movie" on the pages, please review [Installing necessary software] .
... Learning activities
...Teacher's instructions/guide ... Evaluation (expected student responses)
Regarding the necessary software data for using "Cabri 3D File" and "Flash Movie" on the pages, please review [Installing necessary software] .
Learning content
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Based on already acquired experience and knowledge, think about how to create a cylinder in any way other than using a development or parallel translations of (a) plane surface(s). | ||||||||
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Set as learning the observation of what appears when a rectangle is rotated.
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Observe while individually operating Cabri 3D. | ||||||||
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Respond to any student puzzled using the computer. | ||||||||
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Ask what kind of three-dimensional figures are created if plane figures other than a rectangle are rotated. | ||||||||
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Demonstrate how a triangle is rotated.
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Set as learning observation while rotating a triangle and semicircle.
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Observe while individually operating Cabri 3D. | ||||||||
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Respond to any students puzzled using the computer. | ||||||||
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Ask what kind of a three-dimensional figure is created if a plane figure deviated from the axis is rotated. | ||||||||
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Show how a circle deviated from the axis is rotated.
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Set as learning observation while rotating a circle deviated from the axis.
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Set as learning observation while rotating a plane figure including the rotation axis and a plane figure deviated from the axis.
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Introduce to everyone the results of rotating a triangle deviated from the axis in space, and review the situation .
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Describe that a three-dimensional figure (rotation body) can be created by rotating a plane figure around an axis. |
Expected responses from the students
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| B |
It appears that a cylinder will definitely be created by rotating a rectangle.
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| C | It appears that a cylinder will definitely be created even when a vari ety of rectangular shapes are used. |
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| E |
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Rotating a triangle looks like the bead of an abacus.
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| I |
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| K |
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| L | Rotating a triangle deviated from the axis in space looks like electric fan blades . |
| M | It is a common point that all of the three-dimensional figures created by rotating the plain figure look like a circle when viewed from the direction of its axis. |
