I want to draw an image in PHP, which looks like the circle in the following image –
How should I proceed with this? Is there any available PHP plugin or something that I can use to generate this type of image, or should I use GD library and hand-code it myself?
EDIT
I am looking for some library that is open-source.

Do not handcode it yourself as that would be very painful. I once had to code a pie-chart generator.
There are plenty of graph engines out there:
Have a look at what they offer you. Might not be the exact same but something very close.