In geometry, a polygon is traditionally a plane figure that is bounded by a finite chain of straight line segments closing in a loop to form a closed chain. These segments are called its edges or sides, and the points where two of the edges meet are the polygon's vertices (singular: vertex) or corners.
The word polygon comes from Late Latin (a noun), from Greek (/), noun use of neuter of (/, the masculine adjective), meaning "many-angled". Individual polygons are named (and sometimes classified) according to the number of sides, combining a Greek-derived numerical prefix with the suffix -gon, e.g. pentagon, dodecagon. The triangle, quadrilateral and nonagon are exceptions, although the regular forms trigon, tetragon, and enneagon are sometimes encountered as well.
Greek numbers Polygons are primarily named by prefixes from Ancient Greek numbers. + English-Greek numbersEnglish cardinal numberEnglish ordinal numberGreek cardinal numberGreek ordinal numberonefirstheis (fem. mia, neut. hen)protostwosecondduodeuterosthreethirdtreistritosfourfourthtettarestetartosfivefifthpentepemptossixsixthhexhektossevenseventhheptahebdomoseighteighthoktoogdoösnineninthenneaenatostententhdekadekatoseleveneleventhhendekahendekatostwelvetwelfthdodekadodekatosthirteenthirteenthtriskaidekadekatotritosfourteenfourteenthtettareskaidekadekatotetartosfifteenfifteenthpentekaidekadekatopemptossixteensixteenthhekkaidekadekatohektosseventeenseventeenthheptakaidekadekatohebdomoseighteeneighteenthoktokaidekadekatoögdoösnineteennineteenthenneakaidekadekatoënatostwentytwentietheikosieikostostwenty-onetwenty-firstheiskaieikosieikostoprotostwenty-twotwenty-secondduokaieikosieikostodeuterostwenty-threetwenty-thirdtriskaieikosieikostotritostwenty-fourtwenty-fourthtetterakaieikosieikostotetartostwenty-fivetwenty-fifthpentekaieikosieikostopemptostwenty-sixtwenty-sixthhekkaieikosieikostohektostwenty-seventwenty-seventhheptakaieikosieikostohebdomostwenty-eighttwenty-eighthoktokaieikosieikostoögdoöstwenty-ninetwenty-ninthenneakaieikosieikostoënatosthirtythirtiethtriakontatriakostosthirty-onethirty-firstheiskaitriakontatriakostoprotosfortyfortiethtessarakontatessarakostosfiftyfiftiethpentekontapentekostossixtysixtiethhexekontahexekostosseventyseventiethhebdomekontahebdomekostoseightyeightiethogdoëkontaogdoëkostosninetyninetiethenenekontaenenekostoshundredhundredthhekatonhekatostoshundred and tenhundred and tenthdekakaihekatonhekatostodekatoshundred and twentyhundred and twentiethikosikaihekatonhekatostoikostostwo hundredtwo hundredthdiakosioidiakosiostosthree hundredthree hundredthtriakosioitriakosiostosfour hundredfour hundredthtetrakosioitetrakosiostosfive hundredfive hundredthpentakosioipentakosiostossix hundredsix hundredthhexakosioihexakosiostosseven hundredseven hundredthheptakosioiheptakosiostoseight hundredeight hundredthoktakosioioktakosiostosnine hundrednine hundredthenneakosioienneakosiostosOne thousandthousandthchilioichiliostostwo thousandtwo thousandthdischilioidischiliostosthree thousandthree thousandthtrischilioitrischiliostosfour thousandfour thousandthtetrakischilioitetrakischiliostosfive thousandfive thousandthpentakischilioipentakischiliostossix thousandsix thousandthhexakischilioihexakischiliostosseven thousandseven thousandthheptakischilioiheptakischiliostoseight thousandeight thousandthoktakischilioioktakischiliostosnine thousandnine thousandthenneakischilioienneakischiliostosten thousandten thousandthmyrioimyriastostwenty thousandtwenty thousandthdismyrioidismyriastosthirty thousandthirty thousandthtrismyrioitrismyriastosforty thousandforty thousandthtetrakismyrioitetrakismyriastosfifty thousandfifty thousandthpentakismyrioipentakismyriastossixty thousandsixty thousandthhexakismyrioihexakismyriastosseventy thousandseventy thousandthheptakismyrioiheptakismyriastoseighty thousandeighty thousandthoktakismyrioioktakismyriastosninety thousandninety thousandthenneakismyrioienneakismyriastoshundred thousandhundred thousandthdekakismyrioidekakismyriastostwo hundred thousandtwo hundred thousandthikosakismyrioiikosakismyriastosthree hundred thousandthree hundred thousandthtriakontakismyrioitriakontakismyriastosmillionmillionthhekatontakismyrioihekatontakismyriastostwo milliontwo millionthdiakosakismyrioidiakosakismyriastosthree millionthree millionthtriakosakismyrioitriakosakismyriastosten millionten millionthchiliakismyrioichiliakismyriastoshundred millionhundred millionthmyriakismyrioimyriakismyriastos
Systematic polygon names
To construct the name of a polygon with more than 20 and fewer than 100 edges, combine the prefixes as follows. The "kai" connector is not included by some authors. Tensand Onesfinal suffix -kai-1 -hena- -gon20 icosi- (icosa- when used alone) 2 -di-30 triaconta- 3 -tri-40 tetraconta- 4 -tetra-50 pentaconta- 5 -penta-60 hexaconta- 6 -hexa-70 heptaconta- 7 -hepta-80 octaconta- 8 -octa-90 enneaconta- 9 -ennea-
Extending the system up to 999 is expressed with these prefixes. + Polygon namesOnesTensTwentiesThirties+Hundreds10deca-20icosa-30triaconta- 1hena-11hendeca-21icosi-hena-31triaconta-hena-100hecta-2di-12dodeca-22icosi-di-32triaconta-di-200dihecta-3tri-13triskaideca-23icosi-tri-33triaconta-tri-300trihecta-4tetra-14tetrakaideca-24icosi-tetra-40tetraconta-400tetrahecta-5penta-15pentakaideca-25icosi-penta-50pentaconta-500pentahecta-6hexa-16hexakaideca-26icosi-hexa-60hexaconta-600hexahecta-7hepta-17heptakaideca-27icosi-hepta-70heptaconta-700heptahecta-8octa-18octakaideca-28icosi-octa-80octaconta-800octahecta-9ennea-19enneakaideca-29icosi-ennea-90enneaconta-900enneahecta-
List of n-gons by Greek numerical prefixes + List of n-gon namesMost listed names for hundreds do not follow actual Greek number system.SidesNames1henagonmonogon2digonbigon3trigon triangle4tetragonquadrilateral5pentagon6hexagon7heptagonseptagon8octagon9enneagonnonagon10decagon11hendecagonundecagon12dodecagon13tridecagontriskaidecagon14tetradecagontetrakaidecagon15pentadecagonpentakaidecagon16hexadecagonhexakaidecagon17heptadecagonheptakaidecagonseptendecagon18octadecagonoctakaidecagon19enneadecagonenneakaidecagon20icosagon21icosikaihenagonicosihenagon22icosikaidigonicosidigonicosadigon23icosikaitrigonicositrigonicosatrigon24icosikaitetragonicositetragonicosatetragon25icosikaipentagonicosipentagonicosapentagon26icosikaihexagonicosihexagonicosahexagon27icosikaiheptagonicosiheptagonicosaheptagon28icosikaioctagonicosioctagonicosaoctagon29icosikaienneagonicosienneagonicosaenneagon30triacontagon31triacontakaihenagontriacontahenagontricontahenagon32triacontakaidigontriacontadigontricontadigon33triacontakaitrigontriacontatrigontricontatrigon34triacontakaitetragontriacontatetragontricontatetragon35triacontakaipentagontriacontapentagontricontapentagon36triacontakaihexagontriacontahexagontricontahexagon37triacontakaiheptagontriacontaheptagontricontaheptagon38triacontakaioctagontriacontaoctagontricontaoctagon39triacontakaienneagontriacontaenneagontricontaenneagon40tetracontagontessaracontagon41tetracontakaihenagontetracontahenagontessaracontahenagon42tetracontakaidigontetracontadigontessaracontadigon43tetracontakaitrigontetracontatrigontessaracontatrigon44tetracontakaitetragontetracontatetragontessaracontatetragon45tetracontakaipentagontetracontapentagontessaracontapentagon46tetracontakaihexagontetracontahexagontessaracontahexagon47tetracontakaiheptagontetracontaheptagontessaracontaheptagon48tetracontakaioctagontetracontaoctagontessaracontaoctagon49tetracontakaienneagontetracontaenneagontessaracontaenneagon50pentacontagonpentecontagon51pentacontakaihenagonpentacontahenagonpentecontahenagon52pentacontakaidigonpentacontadigonpentecontadigon53pentacontakaitrigonpentacontatrigonpentecontatrigon54pentacontakaitetragonpentacontatetragonpentecontatetragon55pentacontakaipentagonpentacontapentagonpentecontapentagon56pentacontakaihexagonpentacontahexagonpentecontahexagon57pentacontakaiheptagonpentacontaheptagonpentecontaheptagon58pentacontakaioctagonpentacontaoctagonpentecontaoctagon59pentacontakaienneagonpentacontaenneagonpentecontaenneagon60hexacontagonhexecontagon61hexacontakaihenagonhexacontahenagonhexecontahenagon62hexacontakaidigonhexacontadigonhexecontadigon63hexacontakaitrigonhexacontatrigonhexecontatrigon64hexacontakaitetragonhexacontatetragonhexecontatetragon65hexacontakaipentagonhexacontapentagonhexecontapentagon66hexacontakaihexagonhexacontahexagonhexecontahexagon67hexacontakaiheptagonhexacontaheptagonhexecontaheptagon68hexacontakaioctagonhexacontaoctagonhexecontaoctagon69hexacontakaienneagonhexacontaenneagonhexecontaenneagon70heptacontagonhebdomecontagon71heptacontakaihenagonheptacontahenagonhebdomecontahenagon72heptacontakaidigonheptacontadigonhebdomecontadigon73heptacontakaitrigonheptacontatrigonhebdomecontatrigon74heptacontakaitetragonheptacontatetragonhebdomecontatetragon75heptacontakaipentagonheptacontapentagonhebdomecontapentagon76heptacontakaihexagonheptacontahexagonhebdomecontahexagon77heptacontakaiheptagonheptacontaheptagonhebdomecontaheptagon78heptacontakaioctagonheptacontaoctagonhebdomecontaoctagon79heptacontakaienneagonheptacontaenneagonhebdomecontaenneagon80octacontagonogdoecontagon81octacontakaihenagonoctacontahenagonogdoecontahenagon82octacontakaidigonoctacontadigonogdoecontadigon83octacontakaitrigonoctacontatrigonogdoecontatrigon84octacontakaitetragonoctacontatetragonogdoecontatetragon85octacontakaipentagonoctacontapentagonogdoecontapentagon86octacontakaihexagonoctacontahexagonogdoecontahexagon87octacontakaiheptagonoctacontaheptagonogdoecontaheptagon88octacontakaioctagonoctacontaoctagonogdoecontaoctagon89octacontakaienneagonoctacontaenneagonogdoecontaenneagon90enneacontagonenenecontagon91enneacontakaihenagonenneacontahenagonenenecontahenagon92enneacontakaidigonenneacontadigonenenecontadigon93enneacontakaitrigonenneacontatrigonenenecontatrigon94enneacontakaitetragonenneacontatetragonenenecontatetragon95enneacontakaipentagonenneacontapentagonenenecontapentagon96enneacontakaihexagonenneacontahexagonenenecontahexagon97enneacontakaiheptagonenneacontaheptagonenenecontaheptagon98enneacontakaioctagonenneacontaoctagonenenecontaoctagon99enneacontakaienneagonenneacontaenneagonenenecontaenneagon100hectogonhecatontagonhecatogon120hecatonicosagondodecacontagon200dihectagon diacosigon300trihectagon triacosigon400tetrahectagon tetracosigon500pentahectagon pentacosigon600hexahectagon hexacosigon700heptahectagon heptacosigon800octahectagon octacosigon900enneahectagon enneacosigonchiliagondischiliagondichiliagontrischiliagontrichiliagontetrakischiliagontetrachiliagonpentakischiliagonpentachiliagonhexakischiliagonhexachiliagonheptakischiliagonheptachiliagonoctakischiliagonoctachiliagonenneakischiliagonenneachilliagonmyriagondismyriagondimyriagontrismyriagontrimyriagontetrakismyriagontetramyriagonpentakismyriagonpentamyriagonhexakismyriagonhexamyriagonheptakismyriagonheptamyriagonoctakismyriagonoctamyriagonenneakismyriagonenneamyriagondecakismyriagondecamyriagonicosakismyriagonicosamyriagontriacontakismyriagontricontamyriagontetracontakismyriagontetracontamyriagonpentacontakismyriagonpentacontamyriagonhexacontakismyriagonhexacontamyriagonheptacontakismyriagonheptacontamyriagonoctacontakismyriagonoctacontamyriagonenneacontakismyriagonenneacontamyriagonhecatontakismyriagonmegagondiacosakismyriagondimegagontriacosakismyriagontrimegagontetracosakismyriagontetramegagonpentacosakismyriagonpentamegagonhexacosakismyriagonhexamegagonheptacosakismyriagonheptamegagonoctacosakismyriagonoctamegagonenneacosakismyriagonenneamegagonchiliakismyriagondecamegagondischiliakismyriagonicosamegagontrischiliakismyriagontriacontamegagontetrakischiliakismyriagontetracontamegagonpentakischiliakismyriagonpentacontamegagonhexakischiliakismyriagonhexacontamegagonheptakischiliakismyriagonheptacontamegagonoctakischiliakismyriagonoctacontamegagonenneakischiliakismyriagonenneacontamegagonmyriakismyriagonhectamegagongigagonteragonpetagon∞apeirogon
See also Platonic solid Dice List of polygons, polyhedra and polytopes Circle Ellipse Shape