I've written a small Javascript script to make grouped polygon and circle sectors for use in Inkscape. I wrote it to save me time when making certain shapes for a project.
It can also make some nice flower / ferris wheel images if the arc value is set to less than the circle radius.
Pretty basic, but it might save someone else reinventing the wheel ( please forgive the pun

http://www.raincloud.co.uk/svg/svgSector_C.html