Bending a circle

Hi guys,

I'm totally new with grasshopper, I'm now in the process of watching lots of tutorials to get used to the interface and to the concepts and trying to make my first definition and ,,,,ups,,, first issue on the very first step,, I need to bend a circule and have no idea how to do it.

I'm adding here an image of what I'm trying to do without ussing grasshopper, but it would be much bettter to be able to modify the original radius of the circle and the bending angle with grasshopper.

To be more concrete what I did is to move few points of the circle instead of using the "bend" tool of rhino,,,, but I think that the result is one on the same.

Need suggestions to continue my inmersion into grasshopper.

I apologise for my poor english,,, 

Thanks in advance to all,

Joan