圆的知识是初中数学的一个重要内容,在中考中占有相当的份量;与圆有关的题型千姿百态,精彩纷呈.尤其是在光滑的曲线圆上的点在运动变化的题时有出现,由于点的动态引起图形形状发生改变,一些量的大小也发生改变,而所求的结果又是在动中不动——静止不变;常常令学生捉摸不定,无从下手.下面举几例运用圆的知识及其他数学知识来解决圆中的动中有静的问题. Circle of knowledge is an important part of junior high school mathematics, occupy a considerable weight in the examination; with the round-related questions in different poses and in different poses and with different expressions, especially the points on the smooth curve circle in the topic of changes in motion, Point of the dynamic caused by changes in the shape of the figure, some of the amount of the size has changed, and the results are sought again in motion - stationary; often unpredictable students, unable to start. Knowledge and other mathematical knowledge to solve the problem of moving in circles.