I remember you Ruhan :)
How have you been? I see you're having fun studying as usual.
before I answer your question, let me remind you that this is a public board and posting ID and pasword is unwise, to say the least.
I don't need your id, you can just 'share' your work with a link and I'll be able to inspect your code.
Anyhow, no matter what you do you cannot create a perfect circle on a computer. in your code you have to use moveForward(), which is a straight line, however short it is. computer screens are essentially rectangular grids, so you can make it look like a circle from a distance, but it will never lose its straight edges, even if you control it to the last pixel, two pixels will form a line, so... this effort is futile.
Good job thinking about it, though.
Jason.
PS change your password ASAP!! many people have read this post