A diameter. And all the lines that bee drawen crosse the circle, and goe by the centre, are named diameters, whose halfe, I meane from the center to the circumference

any waie, Semi­diameter. is called the semidiameter, or halfe diameter.

But and if the line goe crosse the circle, and passe beside the centre, then is it called a corde, or a stryng line, as I said before, and as this exaumple sheweth: where A. is the corde. And the compassed line that aunswereth to it, An archline is called an arche lyne, A bowline. or a bowe lyne, whiche here marked with B. and the diameter with C.

But and if that part be separate from the rest of the circle (as in this exãple you see) then ar both partes called cãtelles, A cantle the one the greatter cantle as E. and the other the lesser cantle, as D. And if it be parted iuste by the centre (as you see in F.) A semye­circle then is it called a semicircle, or halfe compasse.

Sometimes it happeneth that a cantle is cutte out with two lynes drawen from the centre to the circumference (as G. is) A nooke cantle and then maie it be called a nooke cantle, and if it be not parted from the reste of the circle (as you see in H.) A nooke. then is it called a nooke plainely without any addicion. And the compassed lyne in it is called an arche lyne, as the exaumple here doeth shewe.

An arche.