Translation:A circle does not have only one radius.
This seems like a very odd thing to say, though it is technically correct. On a diagram of a circle you can have more than one radius. I think the reason why this sounds so strange to me is that a radius on a diagram is quite different from the measure of a radius (which is the the same for all the radii in a circle by definition), which is frequently just called 'the radius' in English. I found it a very confusing sentence to translate into English for this reason.
No, I am still puzzled. If you start from the center of a circle and measure outward you get the radius. You can do this numerous times, but the result will always be the same. These aren't varying radii, but the same radius. A circle really can only have one radius. But hey, I am here to practice Greek, even if the logic is a little wonky