Pyramids Divided into Equal Triangular Solids
A shared base yields two solids equal in size and height
Folio 44v continues the pyramid studies, with lettered pen diagrams at the left and further red-chalk tetrahedra ranged down the sheet. The notes divide these solids proportionally, stating that a part a b c d e f amounts to 5/8 of the whole a d e o f, and that the segment a b is half of e f. The final passage argues that a base a b d shared by two pyramids yields two triangular solids equal in size and equal in height.
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One solid is five-eighths of the whole
A lettered diagram is measured proportionally: the portion a b c d e f is stated to be 5/8 of the whole solid a d e o f. A companion note adds that the segment a b is half of e f.
A common base gives two equal triangular solids
The base a b d is said to be common to two triangles equal in quantity, namely the triangle a b d n and the triangle a b d f. They are declared equal in height as well, measured along a n and f b.