this one is a very difficult perfect circle within a perfect circle that i did
in the national circle drawing competition.
it won me second place and probably would have won first if it werent for the
error at about 4 o'clock on the inner circle. it was done with a mid-priced
ball point pen on plain white paper and measures just under 2 inches for the
inner circle and a whopping 3.95 inches for the outer circle (by far my biggest
ever perfect circle).