Figure 4. The ancient Egyptian common (short) cubit and its digit division
(all measures in inches)
Developments

1. BB_{2}C is another reverse image of 3.4.5 triangle ABC and it creates rectangle
ABB_{2}C.

2. A "4" proportion square is drawn on BB_{2}.

3. The "4" square crosses the bottom of the "5" square at R.

4. A vertical line is drawn from A to O on the base of the "5" square.

5. A line is drawn from A to J and a vertical line extends downwards
from J to P on the base
of the "5" square.
Outcomes

1. AJ and OP are 1.4 inches each. AO and JP are 7.4 inches each.

2. Rectangle AJPOA is 17.6 inches, the common cubit.

3. SO is 11/15 inch (0.7333 ...) and exactly 1/24th of rectangle AJPOA 17.6 inches. The
common cubit had 24 digit divisions.

4. Of related interest is the fact that a mile is composed of 1760 yards and the base
perimeter of the Great Pyramid is 1760 royal cubits.
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