21. They aren't perfect squares, but that's as close to perfect squares as you'll ever see. 22. Every odd perfect square is a centered octagonal number. 23. NEW YORK _ Mathematically speaking, Columbus Park in Lower Manhattan is not a perfect square . 24. The county has the unusual distinction of forming a perfect square by Mercator map projection. 25. The third try produces the perfect square of 441. 26. This room is a perfect square , with a lofty dome and trellised windows at its base. 27. Warren Bosworth also invented new stringing patterns like the Bosworth Pattern, perfect squares surrounded by rectangles. 28. The fort was in area and was surrounded by massive walls, forming an almost perfect square . 29. The building has an almost perfect square plan, measuring, having a slight pitch on the roof. 30. The square of an integer may also be called a square number or a perfect square .
