circles - question about red bk example


I’ve forgotten some geometry and was wondering if someone could clarify what the radius of the circle drawn in Ex 2-4 (p48) is supposed to be?

BTW, can running textures in a program keep the color white from showing up as bright as it should?

Thanks very much.

It looks like the circle is draw as sin/cos of angles between 0 and 360. That means the radius will be 1.0

Thanks, also figured out the color problem.