as you may proue by drawing them longer, for so that B.
seme the greater angle yf you make his lines longer then the
lines that make the angle A. And to proue it by demonstration,
I say thus. If any ij. right corners be not equal, then one
right corner is greater then an other, but that corner which is
greatter then a right angle, is a blunt corner (by his
definition) so must one corner be both a right corner and a
blunt corner also, which is not possible: And againe: the lesser
right corner must be a sharpe corner, by his definition, bicause
it is lesse then a right angle. which thing is impossible.
Therefore I conclude that all right angles be equall.

Yf one right line do crosse two other right lines, and make
ij. inner corners of one side lesser then ij. righte corners,
it is certaine, that if those two lines be drawen forth
right on that side that the sharpe inner corners be, they
wil at length mete togither, and crosse on an other.

[Illustration]

The ij. lines beinge as A.B. and C.D, and the third line
crossing them as dooth heere E.F, making ij inner cornes (as ar
G.H.) lesser then two right corners, sith ech of them is lesse
then a right corner, as your eyes maye iudge, then say I, if
those ij. lines A.B. and C.D. be drawen in lengthe on that side
that G. and H. are, the will at length meet and crosse one an
other.

Two right lines make no platte forme.

[Illustration]

A platte forme, as you harde before, hath bothe length and
bredthe, and is inclosed with lines as with his boundes, but ij.
right lines cannot inclose al the bondes of any platte forme.
Take for an example firste these two right lines A.B. and A.C.
whiche meete togither in A, but yet cannot be called a platte
forme, bicause there is no bond from B. to C, but if you will
drawe a line betwene them twoo, that is frome B. to C, then will
it be a platte forme, that is to say, a triangle, but then are
there iij. lines, and not only ij. Likewise may you say of D.E.
and F.G, whiche doo make a platte forme, nother yet can they
make any without helpe of two lines more, whereof the one must
be drawen from D. to F, and the other frome E. to G, and then
will it be a longe rquare. So then of two right lines can bee
made no platte forme. But of ij. croked lines be made a platte
forme, as you se in the eye form. And also of one right line, &
one croked line, maye a platte fourme bee made, as the
semicircle F. doothe sette forth.