| 摘要 |
<p>The present invention relates to a teaching tool for the understanding of shapes which have varying forms depending on a viewing position, wherein the shape appears to be a different form depending on the viewing position. For example, in case of a perfect circle, the perfect circle is seen as a perfect circle from in front of the perfect circle but as an oval if the viewing position is even slightly changed. In addition, even if a plurality of perfect circles are viewed from a position other than the front, the perfect circles appear as different forms of ovals according to the distance thereof. The object of the present invention is to provide a teaching tool for enabling an easy understanding of shapes spaced from each other, in which the forms vary depending on the viewing position and the distance of the shapes. To achieve the object, the best mode of the invention provides a teaching tool in which a hexahedron is formed of a transparent plate, and a plurality of perfect circular rings are fixed inside the hexahedron by regular or varying intervals. Therefore, it is possible to easily understand the changed state of a shape depending on the viewing position and the changing forms of shapes which differ from one another depending on the distance of the shapes.</p> |
