When I did maths at school I used to like geometry, especially anything involving circles. Now the only time I use maths regularly is when I'm working out what something will cost with 20% off and when I'm sewing. Making a pattern for a circle skirt combines my love of sewing with the fun (totally subjective) of geometry. It's probably one of the easiest patterns to make yourself. Basically, it's just a big circle with a smaller circle in the middle the size of your waist. Mine's actually made up of four pieces, rather than two half circles, because I wanted the stripes to be in a chevron pattern. Sadly, I spent ages cutting out the pieces and matching up all the seams and you don't actually notice the chevron pattern when I wear it.
The fabric is a thin cotton with purple stripes. I used about three metres to make this skirt but that was mostly because it wasn't very wide and I needed to match the stripes.
(Also, I always seem to look unhappy in my photos. I'm not. It's just I feel weird grinning like an idiot when I take self-timer photos and they always end up looking strange and forced).