What does pentagonal mean?
Pentagonal is the adjective for something shaped like a pentagon, meaning that it has five straight sides and five angles. The word is especially common in geometry, where it describes a particular class of polygon, but it is also useful in architecture, graphic design, engineering, and descriptions of objects. For example, a building may have a pentagonal floor plan, while a sign or sculpture may use a pentagonal outline. The adjective is more formal than the simpler phrase five-sided, so it is especially appropriate in technical or descriptive contexts. Although pentagonal is relatively uncommon in everyday conversation, it provides a precise way to name a form that is less usual than the familiar square, rectangle, or triangle.
adjectiveHaving five sides and five angles, or relating to a five-sided geometric figure.
- Having the form or structure of a five-sided polygon.
- Relating to or characteristic of pentagons, especially in geometry, architecture, or design.
"The architect designed a pentagonal courtyard at the center of the building."
"The team worked out a pentagonal arrangement for the five display stands."
"The pentagonal window is characteristic of the building's modern design."
A pentagonal shape brings to mind a five-pointed star, but the word describes a polygon with five straight sides and five interior angles.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does pentagonal come from?
Pentagonal comes from Latin pentagonalis, meaning “having five angles.” That form was derived from the Greek pentagōnos, a compound of pente, “five,” and gōnia, “angle.” The same Greek elements underlie related words such as pentagon and pentagram.
Related word forms
How pentagonal is actually used
This is a formal or technical adjective, used especially in mathematics, architecture, design, and descriptions of geometric objects. In general writing, five-sided is often more accessible.
Easily confused with pentagonal
A pentagon is the five-sided shape itself, while pentagonal is an adjective describing something that has that shape.