Possible Clues:

• Having all sides of the same length
• Triangle in which all three sides are of equal length
• One subsequently blocks peer keeping the sides the same
• Like regular shapes, all are quite different
• Having all sides of equal length
• Regular English writer of old, about at the time
• Like diamonds, for example, all are quite different
• Peer round vertical line in due course to view square, perhaps
• Having all sides the same length
• With all sides equal