To make a circle about any sise angle limited of equall
sides and equall angles.
Bicause you maye easily coniecture the makinge of these figures
by that that is saide before of cinkangles, only consideringe
that there is a difference in the numbre of sides, I thought
beste to leue these vnto your owne deuice, that you should study
in some thinges to exercise your witte withall and that you
mighte haue the better occasion to perceaue what difference
there is betwene eche twoo of those conclusions. For thoughe it
seeme one thing to make a siseangle in a circle, and to make a
circle about a siseangle, yet shall you perceaue, that is not
one thinge, nother are those twoo conclusions wrought one way.
Likewaise shall you thinke of those other two conclusions. To
make a siseangle about a circle, and to make a circle in a
siseangle, thoughe the figures be one in fashion, when they are
made, yet are they not one in working, as you may well perceaue
by the xxxvij. xxxviij. xxxix. and xl. conclusions, in whiche
the same workes are taught, touching a circle and a cinkangle,
yet this muche wyll I saye, for your helpe in working, that when
you shall seeke the centre in a siseangle (whether it be to make
a circle in it other about it) you shall drawe the two
crosselines, from one angle to the other angle that lieth
againste it, and not to the middle of any side, as you did in
the cinkangle.