包含学生信息管理的基本功能，能够实现对学生的学籍、成绩、基本信息进行管理！-Student Information Management includes the basic functions of any pupil to achieve results, the basic information management!

一个简单圆，有圆心半径，已知半径，求周长和面积。已知某点求是否在圆上。-A simple circle, a circle radius, known radius, strives for the pupil. Known to some point whether in the round.