Creative
Step 1 - Open up the spread sheet and in A1 type in X^2+Y^2=1 to get the circle centered.
Step 2 - Add one point and name it P.
Step 3 - add slider that is called a slider interval, leave the minutes at -2 and the maximum that it shows at 2. Then add an increment of 0.01. Finally go to the option where it says slider and place it for 200 pixels.
step 4 - add another slider but place this one for angels instead of intervals. and all you must do is go to the slider and place with at the width of 200.
step 5 - On the spreadsheet type into A2 Rotate[Dilate[A1,r,P],t,P].
Step 6 - drag that down into 16 or 20 of the other A boxes.
step 7 - right click on sliders and press animation
your all done.
If wanted u can change the first step to 2x^2+Y^2=1