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left:
top:
The formula used for this circle is:

     left(t) = radius * cos(t) + xcenter
     top(t) = radius * sin(t) + ycenter

Left is the number of pixels from the left of the screen and top is the number of pixels from the top of the screen. The radius of this particular circle is 100 pixels. The range of t is [0,4π]. the step of t is 0.1.

I got this formula from Math.com. A site for children.

The behavior of this function is inexplicable. I don't know why it accelerates and decelerates, but it does.