圆作为小学阶段最后学习的一个平面图形,与其他平面图形相比,有其非常特殊的一些性质、特征。除了周长的定义与其他图形有相似之处以外,其他名称也与长方形、正方形、三角形等平面图形有一定的区别,比如:半径、直径等,当然还有我们引以为傲的圆周率,这些都是圆所特有 The circle, as a flat figure of the final study in the elementary school, has some very special characteristics and features compared with other flat figures. In addition to the definition of perimeter and other graphics have similarities, other names and rectangles, squares, triangles and other planar graphics are some differences, such as: radius, diameter, etc., of course, we are proud of the pi, these All are unique