Take your fabric and fold it in half, and
in half again, so you have your fabric folded in quarters.
So, I am going to make a circle skirt with
a 21” waist circumference (C). Using this number, I determined the
radius of the waistline/inner circle:
waist radius = C/2*3.14
waist radius = 21/6.28
waist radius = 3.34
Mark a quarter circle on the folded corner
of your fabric, using this radius measurement. This circle will be
your stitching line.
Then mark another quarter circle, 1/2"
closer to the corner, for seam allowance. This circle will be your