Definition of "heptagonal" [hep•tag•o•nal]

• Having seven angles and sides. (adjective)

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• "The final part of the instillation is a great heptagonal glass case in a darkened room."
• "Both figures are comprised of a single recursive line, suggesting that the selection of the heptagonal figure was deliberate."
• "Regarding the visual pattern of the heptagonal figure at Urbino, it is worth considering Hugh of St. Victor's thoughts on the mnemonic potentials of geometry."