If I am given the circumference(2368)

how can I find the diameter and the radius?

Work backward with what you know. The formula for circumference is 2*pi*r. Solve for this and you will have the radius. So, 2*3.14*r = 2368

6.28r = 2368 Divide both sides by 6.28.
This will give you the radius. Just mulriply it by 2 and you will have the diameter.
Hope this is helpful