Reference for Eruvin 113:9

אמר ליה רב חנילאי מחוזנאה לרב אשי מכדי כמה מרובע יתר על העגול רביע הני תמני מאה שית מאה ושיתין ושבע נכי תילתא הוי

to R'Ashi: Are there not, however, the projections of the corners?<span class="x" onmousemove="('comment',' Which reduce the area of the open spaces which, in consequence, would represent less than a quarter of the corners.');">¹⁵</span> - The reference is to a circular city.<span class="x" onmousemove="('comment',' A circle has no projecting corners.');">¹⁶</span> Was it not, however, made square?<span class="x" onmousemove="('comment',' As stated supra.');">¹⁷</span>

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