Circle with thick line

I'm trying to draw a circle that has a THICK line.
I tried using setPenWidth(10) but that only resulted in a circle that looks odd.

I'm currently using fillCircle and basically drawing 2 circles on top of each other to cancel out the areas I don't want.
however, this then comes w/ another issue - because of this 'cancel' out circle, i'm effectively making the screen white and I have to be careful where i put the code and / or other code else i don't get any output.

So, I'm perplexed and asking if there is a better alternative to doing what I need.

thoughts?