For a pyramis in solids, is as a triangle is in plaines. For a pyramis may be resolved into other solid figures, but it cannot be resolved into any one more simple than it selfe, and which consists of fewer sides than it doth.
Therefore
14 Pyramides of equall heighth, are as their bases are
And
15 Those which are reciprocall in base and heighth are equall 9 p xij.
These consectaries are drawne out of the [16], [18 e. iiij].
