The reason or rate of a section is thus: The similitude doth follow.
15 If sections doe receive [or containe] equall angles, they are alike è 10. d iij.
As here aei, and ouy. The triangle here inscribed, seeing they are equiangles, by the grant; they shall also be alike, by the [12 e vij].
16 If like sections be upon an equall base, they are equall: and contrariwise. 23, 24. p iij.
In the first figure, let the base be the same. And if they shall be said to unequall sections; and one of them greater than another, the angle in that aoe, shall be lesse than the angle aie, in the lesser section, by the [16 e vj]. which notwithstanding, by the grant, is equall.
In the second figure, if one section be put upon another, it will agree with it: Otherwise against the first part, like sections upon the same base, should not be equall. But congruency is here sufficient.
By the former two propositions, and by the [9 e xv]. one may finde a section like unto another assigned, or else from a circle given to cut off one like unto it.