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Revision difference : Egyptian geometry areas calculated in, cubits, khets and setats
Version 15 Version 14
A scribal area of triangles and other shapes area calculation method is reported by three \PMlinkexternal{Rhind Mathematical Papyrus}{http://ahmespapyrus.blogspot.com/2009/01/ahmes-papyrus-new-and-old.html} problems \PMlinkexternal{RMP 53-55}{http://rmp50-60.blogspot.com/}. The scribal geometry utilized quotients and remainders in an arithmetic context that was also applied in scribal weights and measures, algebra, and 2/n tables. A scribal area of triangles and other shapes area calculation method is reported by three \PMlinkexternal{Rhind Mathematical Papyrus}{http://ahmespapyrus.blogspot.com/2009/01/ahmes-papyrus-new-and-old.html} problems \PMlinkexternal{RMP 53-55}{http://rmp50-60.blogspot.com/}. The scribal geometry utilized quotients and remainders in an arithmetic context that was also applied in scribal weights and measures, algebra, and 2/n tables.
RMP 53 calculated the area of two triangles, of 45/8 setat and 63/8 setat, and a third area of an undefined shape by the note, 1/10 of 1 3/8 mh added to 10 cubits of land (COL) is the desired area. A setat was 100 cubit by 100 cubit, or 10,000 square cubits. A cubit of land (COL) was one cubit wide by 100 cubits long, or 1/100 setat. A mh unit may have been 10 setat (or less likely 1/10 setat). RMP 53 calculated the area of two triangles, of 45/8 setat and 63/8 setat, and a third area of an undefined shape by the note, 1/10 of 1 3/8 mh added to 10 cubits of land (COL) is the desired area. A setat was 100 cubit by 100 cubit, or 10,000 square cubits. A cubit of land (COL) was one cubit wide by 100 cubits long, or 1/100 setat. A mh unit may have been 10 setat (or less likely 1/10 setat).
The first triangle had an altitude of 5 khet and a base of 9/4 khet. Using the area of a triangle formula, 1/2 the base times the altitude, 5 x 9/4 x 1/2= 45/8 setat. The first triangle had an altitude of 5 khet and a base of 9/4 khet. Using the area of a triangle formula, 1/2 the base times the altitude, 5 x 9/4 x 1/2= 45/8 setat.
The second triangle had an altitude of 7 khet and a base of 9/4 khet. Using the area of a triangle formula, 1/2 the base times the altitude, Ahmes calculated 7 x 9/4 x 1/2 = 63/8 setat The second triangle had an altitude of 7 khet and a base of 9/4 khet. Using the area of a triangle formula, 1/2 the base times the altitude, Ahmes calculated 7 x 9/4 x 1/2 = 63/8 setat
The third calculation found the area of undefined shape was discussed by: The third calculation found the area of undefined shape was discussed by:
11/8 mh = 110/8 setat + 10 COL = (110/8 + 10/100)setat = (1100/80 + 10/80) setat = 111/8 setat = 13 7/8 setat, 11/8 mh = 110/8 setat + 10 COL = (110/8 + 10/100)setat = (1100/80 + 10/80) setat = 111/8 setat = 13 7/8 setat,
or, less likely, or, less likely,
11/8 mh = 110/8 COL + 10 COL = (1100 + 800)/80 COL = 190/8 = 23 3/4 COL 11/8 mh = 110/8 COL + 10 COL = (1100 + 80)/80 COL = 118/8 = 14 3/4 COL
As a triangle, as implied by Ahmes' annotated diagram, the third shape had a base 6 khet, an altitude of 37/8 khet and an area of 111/8 setat. The area calculation would have been 6 x 37/8 x 1/2 = 111/8 setat. As a triangle, as implied by Ahmes' annotated diagram, the third shape had a base 6 khet, an altitude of 37/8 khet and an area of 111/8 setat. The area calculation would have been 6 x 37/8 x 1/2 = 111/8 setat.
Others have suggested that a trazazoid may define the area. To assist the proper decoding of the third RMP 53 area, RMP 54 and RMP 55 will be consulted.
To assist the decoding of the third RMP 53 area, RMP 54, and RMP 55 details will be consulted.
RMP 54 segmented 7/10 setat by 10, 5, 2 1/2 and 1 1/4 fields. Proof was provided by finding setat + COL areas of 7/10, 14/10, 28/10 and 56/10 setats fields within quotient and remainder data: RMP 54 segmented 7/10 setat by 10, 5, 2 1/2 and 1 1/4 fields. Proof was provided by finding setat + COL areas of 7/10, 14/10, 28/10 and 56/10 setats fields within quotient and remainder data:
a. 7/10*(4/4) = 28/40 = (24 + 3)/40 = 3/8 setat + 300/40 COL = 5/8 setat + 7 1/2 COL a. 7/10*(4/4) = 28/40 = (24 + 3)/40 = 3/8 setat + 300/40 COL = 5/8 setat + 7 1/2 COL
b. 14/10*(4/4) = 56/10 = (55 + 1)/40 = 11/8 setat + 100/4 COL = 1 3/8 setat + 2 1/2 COL b. 14/10*(4/4) = 56/10 = (55 + 1)/40 = 11/8 setat + 100/4 COL = 1 3/8 setat + 2 1/2 COL
c. 28/10*(2/2) = 56/20 = (55 + 1)/20 = 11/4 setat + 100/20 COL = 2 3/4 setat + 5 COL c. 28/10*(2/2) = 56/20 = (55 + 1)/20 = 11/4 setat + 100/20 COL = 2 3/4 setat + 5 COL
d. 56/10 = (55 + 1)/10 = 11/2 setat + 100/10 COL = 5 1/2 setat + 10 COL d. 56/10 = (55 + 1)/10 = 11/2 setat + 100/10 COL = 5 1/2 setat + 10 COL
RMP 55 is a work-in-progress. A translation is nearing completion.
\begin{thebibliography}{9} \begin{thebibliography}{9}
\bibitem{1} Milo Gardner, \emph{The Egyptian Mathematical Leather Roll Attested Short Term and Long Term, History of Mathematical Sciences}, Hindustan Book Company, 2002. \bibitem{1} Milo Gardner, \emph{The Egyptian Mathematical Leather Roll Attested Short Term and Long Term, History of Mathematical Sciences}, Hindustan Book Company, 2002.
\bibitem{2} Milo Gardner, \emph{An Ancient Egyptian Problem and its Innovative Solution, Ganita Bharati}, MD Publications Pvt Ltd, 2006. \bibitem{2} Milo Gardner, \emph{An Ancient Egyptian Problem and its Innovative Solution, Ganita Bharati}, MD Publications Pvt Ltd, 2006.
\bibitem{3}Richard Gillings, \emph{Mathematics in the Time of the Pharaohs}, Dover Books, 1992. \bibitem{3}Richard Gillings, \emph{Mathematics in the Time of the Pharaohs}, Dover Books, 1992.
\bibitem{4} Oystein Ore, \emph{Number Theory and its History}, McGraw-Hill Books, 1948, Dover reprints available. \bibitem{4} Oystein Ore, \emph{Number Theory and its History}, McGraw-Hill Books, 1948, Dover reprints available.
\bibitem{5} T.E. Peet, \emph{Arithmetic in the Middle Kingdom}, Journal Egyptian Archeology, 1923. \bibitem{5} T.E. Peet, \emph{Arithmetic in the Middle Kingdom}, Journal Egyptian Archeology, 1923.
\bibitem{6} Tanja Pommerening, \emph{"Altagyptische Holmasse Metrologish neu Interpretiert" and relevant phramaceutical and medical knowledge, an abstract, Phillips-Universtat, Marburg, 8-11-2004, taken from "Die Altagyptschen Hohlmass}, Buske-Verlag, 2005. \bibitem{6} Tanja Pommerening, \emph{"Altagyptische Holmasse Metrologish neu Interpretiert" and relevant phramaceutical and medical knowledge, an abstract, Phillips-Universtat, Marburg, 8-11-2004, taken from "Die Altagyptschen Hohlmass}, Buske-Verlag, 2005.
\bibitem{7} Gay Robins, and Charles Shute \emph{Rhind Mathematical Papyrus}, British Museum Press, Dover reprint, 1987. \bibitem{7} Gay Robins, and Charles Shute \emph{Rhind Mathematical Papyrus}, British Museum Press, Dover reprint, 1987.
\bibitem{8} L.E. Sigler, \emph{Fibonacci's Liber Abaci: Leonardo Pisano's Book of Calculation}, Springer, 2002. \bibitem{8} L.E. Sigler, \emph{Fibonacci's Liber Abaci: Leonardo Pisano's Book of Calculation}, Springer, 2002.
\bibitem{9} Hana Vymazalova, \emph{The Wooden Tablets from Cairo:The Use of the Grain Unit HK3T in Ancient Egypt, Archiv Orientalai}, Charles U Prague, 2002. \bibitem{9} Hana Vymazalova, \emph{The Wooden Tablets from Cairo:The Use of the Grain Unit HK3T in Ancient Egypt, Archiv Orientalai}, Charles U Prague, 2002.
\end{thebibliography} \end{thebibliography}