![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/ab/FS_C.png/220px-FS_C.png)
The circle as base element.
General case
editSegments in the general case
editThe radius of the circle
Perimeters in the general case
editPerimeter of base circle:
Areas in the general case
editArea of the base circle:
Centroids in the general case
editCentroid positions are measured relative to the centroid point of the base element.
Centroid positions of the base circle:
Normalised case
editIn the normalised case the area of the base circle is set to 1.
So
Segments in the normalised case
editSegment of the base circle
Perimeters in the normalised case
editPerimeter of base circle
Areas in the normalised case
editArea of the base circle is by definition
Centroids in the normalised case
editCentroid positions of the base circle:
Identifying number
editApart of the base element there is no other shape allocated. Therefore the integer part of the identifying number is 0.
The decimal part of the identifying number is the decimal part of the sum of the perimeters and the distances of the centroids in the normalised case.
So the identifying number is: