在我们的生活中,圆形的物体是随处可见的,如:硬币、车轮、锅盖、圆形钟面、奥运五环、易拉罐的底面、水管的截面等都是圆形的。为什么车轮要做成圆形的呢?如果车轮做成三角形、四边形或其他的形状,人们坐在车上就会一会儿高、一会儿低,不把头颠晕了才怪呢?而车轮做成圆形的,因为同一个圆中所有的半径都相等,也就是车轮轴心到地面的距离始终保持不变,这样车子 In our life, round objects are everywhere, such as coins, wheels, pots, round clock face, Olympic rings, the bottom of the cans, the cross-section of the water pipes are all round. Why the wheel to be made round it? If the wheel made of triangles, quadrilateral or other shapes, people sitting in the car will be a while high, while a low, headless Britain dazzle it strange? The wheel made of round , Because all the same radius of the circle are equal, that is, the distance between the wheel axis to the ground remains unchanged, so the car