Draw part of a circle

Question

For an iPhone application I want to draw a circle, that is only for an x percentage filled.

Something like this:

Answer 1

Try this:

CGContextMoveToPoint(the center point)
CGContextAddLineToPoint(the starting point of the fill path on the circumference)
CGContextAddArcToPoint(the ending point of the fill path on the circumference)
CGContextAddLineToPoint(the center point)
CGContextFillPath