Circle is Bisected by Diameter/Historical Note

Historical Note on Circle is Bisected by Diameter
The result that a Circle is Bisected by Diameter was supposedly attributed to by.

defines the diameter as the line which passes through the center, but then assumes that it necessarily bisects it:



According to in his :
 * It seems strange that, a disciple of the Egyptians, should bother to demonstrate something which takes as self-evident.  suggests that he proved it by folding the circle over the diameter.