1.
Definition: A strophoid of a circle with the pole O at the centre of the circle and the fixed point P on the circumference of the circle.
定义：在圆上的环索线，以圆心为极点，圆周上的一点为固定点，所作出的图形！
2.
That point falls on the circumference of the circle.
那一个点落在这圆的圆周线上。
3.
A point equidistant from all points on the circumference of a circle or on the surface of a sphere.
圆心，球心与一圆周上或一球面上所有点等距的一点
4.
The curve traced by a point on the circumference of a circle that rolls on a straight line.
圆滚线，摆线圆周上任一点在一条直线上滚动时所形成的曲线
5.
"cardioid:a heart-shaped plane curve, the locus of a fixed point on a circle that rolls on the circumference of another circle with the same radius."
心脏线:一种心形的平滑曲线,圆周上一固定点绕另一具有相同半径的圆的圆周转动的轨迹.
6.
A heart-shaped plane curve, the locus of a fixed point on a circle that rolls on the circumference of another circle with the same radius.
心脏线一种心形的平滑曲线，圆周上一固定点绕另一具有相同半径的圆的圆周转动的轨迹
7.
The curve described by a point on the circumference of a circle as the circle rolls on the outside of the circumference of a second, fixed circle.
外摆线一个动圆沿另一个定圆外侧滚动时，动圆圆周上一点的轨迹曲线
8.
The plane locus of a point fixed on a circle that rolls on the inside circumference of a fixed circle.
圆内旋转线，内摆圆在一个固定的圆周内旋转的圆上一点的水平轨迹
9.
A line segment that joins the center of a circle with any point on its circumference.
圆半径将圆心与圆周上任一连接起来的线段
10.
The boundary line of a circle.
圆周一个圆的边界线
11.
Circumference:The boundary line of a circle.
圆周:一个圆的边界线.
12.
Why not simply specify starting and ending points on the circumference of the ellipse?
为什么不简单地指定椭圆的圆周上的开始和结束的点呢？
13.
One instance of simple harmonic motion is that of the projection on any diametre of a point which describes a circular path with uniform angular velocity.
当一质点以匀角速度作圆周运动时，则它在任意直径上的投影的运动便是简谐运动的一例。
14.
a line generated by a point on a circle rolling around another circle.
一个圆上的某点在该圆旋转另一个圆时产生的线。
15.
Flat- A section of the perimeter of a wafer that has been removed for wafer orientation purposes.
平边-晶圆片圆周上的一个小平面，作为晶向定位的依据。
16.
The circular points are really a degenerate conic.
虚圆点实际上是一退化的二次曲线。
17.
A curve traced by a point on or connected with a circle as the circle rolls along a fixed straight line.
旋转线，次摆线圆在固定直线上滚动时，圆上一点或与圆相连的一点的弧形轨迹
18.
a projection of the globe onto a cone with its point over one of the earth's poles.
把地球的投影图做到一个圆锥上圆锥的顶点是地球的一极。