gles , Triangles, Squares, Circles, Ovals, &c.
other Figures which it is sufficient at hrst to
ie acquainted with before we venture on them,:
for you see here are two Feints ; A and' 0,
which may be. joined fc A o
may be called it Raj' a-.—o
or Semidiameter when ——
you- make- a Circle of it/ \^
If you lengthen A. O.with another Ray or an
other Semidiamer.you will have- a whoteDiametrr.
Of which 0 is here
ATX. orXTA.make a
T.O.is a Perpendicular'. J