Pronunciation: [pɛntˈaɡənə͡l] (IPA) 
The word "pentagonal" is spelled with a "p" followed by the IPA symbol for "eh" (/ɛ/), then "n", "t", "a", "g", "o", and "n" in that order. The "p" at the beginning of the word is silent, so the stress falls on the second syllable. The word comes from the root "penta-", meaning five, and "-gon", meaning angle or corner, and it refers to a shape that has five sides or angles.
Pentagonal is an adjective that describes anything relating to a shape with five sides or elements. Derived from the combination of "pentagon" and the suffix "-al" denoting a characteristic or quality, the term is commonly used in mathematics, geometry, and related fields.
In the realm of geometry, pentagonal refers to a polygon with five straight sides and five angles. Each angle in a pentagon measures 108 degrees. Additionally, a regular pentagon is one in which all sides and angles are equal. However, a pentagonal shape can also refer to any object or structure made up of five distinct elements or sides.
The term pentagonal is frequently employed in various scientific disciplines, architecture, and art. In chemistry, it is used to describe a specific molecular structure with five atoms bonded to a central atom. Moreover, pentagonal arrangements can be seen in various natural objects, from the cells in a honeycomb to certain types of sea urchins.
In common everyday language, pentagonal may refer to any object, design, or layout that resembles the shape of a pentagon. This can include buildings, gardens, or even sports fields. Artists and designers often employ the symmetrical and balanced qualities of a pentagonal shape to create aesthetically pleasing compositions.
Overall, the term pentagonal relates to the nature, form, or property associated with a shape having five sides or corresponding elements in various fields of study, providing a versatile and fundamental descriptive term.
Having five corners or angles.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "pentagonal" has its roots in Greek. It is derived from the combination of two Greek words: "pente", meaning "five", and "gonia", meaning "angle" or "corner". When these two words are combined, they form "pentagon", which refers to a polygon with five sides and five angles. "Pentagonal" is the adjective form of "pentagon" and is used to describe anything that has the shape or characteristics of a pentagon.
