Three alternate methods of obtaining the ancient Egyptian formula for the area of a circle (Q1061721)

To determine the area of a circle, mathematicians in ancient Egypt used the square of 8/9 of its diameter. This gave the approximation of \(\pi\) equal 3,1605. The reviewed paper is devoted to the question: how could the Egyptian formula have been found. After a description of earlier attempts to answer this question the author presents three new conjectures: first two of them are suggested by an examination of African craft technique, the third one by playing with circular objects.