Fourth: a line of 12 divided into 4 and 8
Square on the lesser part (16) and rectangle of the two parts (32)
Headed as the 'Fourth', the sheet divides a line of 12 at the point c into a lesser part 4 and a greater part 8. On the smaller part a square of area 16 is built, and on the two parts together a rectangle of 32, while the greater part squared gives 64 and the whole 144. A block of numbers works the same quantities, and one figure of the divided line is marked as struck out.
On this page
Square and rectangle applied to the divided line
On the line divided into 4 and 8, a square of 16 is raised on the lesser part and a rectangle of 32 on the two parts together. The pairing shows the square of a part and the rectangle of the parts side by side.
Line of 12 divided at c into 4 and 8
A line of length 12 is cut at the point c, giving a segment a-c of 4 and a segment c-b of 8. This division supplies the parts from which the squares and rectangles are built.
Column of arithmetic on the parts
A block of figures carries out the operations on the same numbers, among them 4 and 8, 16, 32, 64 and 144. It reproduces in calculation the areas drawn in the figures.