Polygons: English Vocabulary List

a two-dimensional closed shape with straight sides and equal angles between adjacent sides, and all sides have the same length

"Regular polygons have equal sides."

"A regular polygon has all sides equal in length and all interior angles equal in measure."

a polygon that does not have all sides or angles equal in size or measure, making it non-regular and lacking symmetry

"Irregular polygons have unequal sides."

"An irregular polygon has sides and angles that are not all equal so its shape is not perfectly symmetric."

a geometric shape that has all its interior angles measuring less than 180 degrees, causing the polygon to curve outward

"Convex polygons bulge outward."

"A convex polygon has all interior angles less than one hundred eighty degrees and bulges outward."

a geometric shape that has at least one angle measuring greater than 180 degrees, causing the polygon to curve inward

"Concave polygons have an indentation."

"A concave polygon has at least one interior angle greater than one hundred eighty degrees creating an inward dent."

a geometric shape with five angles and five straight sides

"A pentagon has five."

"The United States Department of Defense headquarters is famously known as the Pentagon due to its five-sided geometric shape."

(geometry) a closed shape with six straight sides and six angles

"A hexagon has six sides."

"A hexagon is a polygon with six sides and six angles, commonly found in nature."

a seven-sided plane shape consisting of seven line segments or edges that meet at seven interior angles

"A heptagon has seven sides."

"The architectural design featured a unique heptagon shape for the central courtyard, creating an unusual space."

(geometry) a polygon consisting of eight straight sides and eight angles

"An octagon has eight sides."

"The stop sign is a familiar example of an octagon, a polygon with precisely eight equal sides and angles."

(geometry) a flat shape consisting of nine straight sides and nine angles

"A nonagon has nine."

"A nonagon is a geometric figure that possesses nine straight sides and nine corresponding angles."

(geometry) a flat polygon with ten straight sides and ten angles

"A decagon has ten."

"A decagon is a polygon characterized by having exactly ten straight sides and ten interior angles."

(geometry) a flat figure consisting of eleven straight sides and eleven angles

"A regular hendecagon has eleven equal sides."

"The hendecagon is a rarely seen polygon that has eleven sides and eleven interior angles."

(geometry) a flat figure that consists of twelve sides and twelve angles

"The twelve-sided figure is a dodecagon."

"The architect incorporated the precise angles of a dodecagon into the unique design of the building."

a polygon with fourteen sides and fourteen angles

"A tetradecagon has fourteen sides."

"A tetradecagon is a polygon with fourteen sides and fourteen interior angles adding up to two thousand one hundred sixty degrees."

a polygon with thirteen sides and thirteen angles

"The tridecagon is a polygon with thirteen sides."

"The tridecagon is a thirteen sided polygon that appears in some geometric puzzles and architectural details."

a polygon with fifteen sides and fifteen angles

"Pentadecagon has fifteen sides."

"A pentadecagon is a fifteen sided polygon that is rarely seen in everyday geometry but exists mathematically."

a polygon with sixteen sides and sixteen angles

"Hexadecagon has sixteen sides."

"A hexadecagon is a sixteen sided polygon that can be regular or irregular in its shape."

a polygon with seventeen sides and seventeen angles

"Heptadecagon has seventeen sides."

"A heptadecagon is a seventeen sided polygon that was proven constructible by the mathematician Gauss."

a polygon with eighteen sides and eighteen angles

"Octadecagon has eighteen sides."

"An octadecagon is an eighteen sided polygon that has interior angles summing to two thousand eight hundred eighty degrees."

a polygon with nineteen sides and nineteen angles

"Enneadecagon has nineteen sides."

"An enneadecagon is a nineteen sided polygon a shape that is rarely encountered in practical geometry problems."

a polygon with twenty sides and twenty angles

"An icosagon has twenty sides."

"An icosagon is a polygon with twenty sides"

a five-pointed star

"The ancient symbol was a pentagram inside a circle."

"The pentagram is a five pointed star often used as a symbol in various religious and occult traditions."

(geometry) a flat star-shaped figure with six points that can be formed by making equilateral triangles on each side of a regular hexagon

"A hexagram is a six-pointed star formed from two overlapping triangles."

"The geometric hexagram is a six-pointed star formed by two overlapping equilateral triangles."

a three-sided geometric shape

"Trilateral means three-sided shape."

"A trilateral is another name for a triangle which is a three sided polygon."