Eaghtyr

She yn mooad towse-oaylleeagh bun-chooish y duillag shoh. My vel anaase ayd ayns keeal elley yn 'ockle shoh, lhaih Eaghtyr (reddaghey).

Ta'n fockle eaghtyr ny chur sheese er mooad ta fockley mooadys daa-howshanagh er rheynn vaghtal jeh baare, eaghtyr ny crackan, ta caglit liorish cruill ghooint. Ta'n enmys ny chur sheese er slane eaghtyr baare, eaghtyr ny crackan anchoodit jeh stooalt tree-howshanagh, lheid as sym eaghtyryn jeh çheughyn anchoodit polyheedrane.

Ta unnidyn ry hoi towshanagh eaghtyr goaill stiagh lheid as:

are (a) = 100 meteryn kerrinagh (m²)

hectare (ha) = 100 areyn (a) = 10000 meteryn kerrinagh (m²)

kilometer kerrinagh (km²) = 100 hectareyn (ha) = 10000 areyn (a) = 1000000 meteryn kerrinagh (m²)

mooar-veter kerrinagh (Mm²) = 10¹² meteryn kerrinagh

trie cherrinagh = 144 oarlee cherrinagh = 0.09290304 meteryn kerrinagh (m²)

stundayrt kerrinagh = 9 trieyn kerrinagh (0.84 m²) = 0.83612736 meteryn kerrinagh (m²)

perçh kerrinagh = 30.25 stundayrtyn kerrinagh = 25.2928526 meteryn kerrinagh (m²)

meeilley cherrinagh = 640 acyryn (2.6 km²) = 2.5899881103 kilometeryn kerrinagh (km²)

Formley cadjin da eaghtyr:

Cummey	Cormid	Ceaghlee
Kerrin	${\displaystyle s^{2}\,\!}$	She ${\displaystyle s}$ lhiurid un çheu y cherrin.
Troorane cadjin (troorane co-lhiatteeagh)	${\displaystyle {\frac {\sqrt {3}}{4}}s^{2}\,\!}$	She ${\displaystyle s}$ lhiurid un çheu y troorane.
Shey-lhiattaghan cadjin	${\displaystyle {\frac {3{\sqrt {3}}}{2}}s^{2}\,\!}$	She ${\displaystyle s}$ lhiurid un çheu y shey-lhiattaghan.
Hoght-lhiatteeane cadjin	${\displaystyle 2\left(1+{\sqrt {2}}\right)s^{2}\,\!}$	She ${\displaystyle s}$ lhurid un çheu y hoght-lhiatteeane.
Yl-lhiatteeane cadjin erbee	${\displaystyle {\frac {1}{2}}ap\,\!}$	She ${\displaystyle a}$ yn apothem, ny craue raadeeoil jeh kiarkyl grainnit 'syn yl-lhiatteeane, as she ${\displaystyle p}$ ym-linney yn yl-lhiatteeane.
Yl-lhiatteeane cadjin erbee	${\displaystyle {\frac {ns^{2}}{4\cdot \tan(\pi /n)}}\,\!}$	She ${\displaystyle s}$ y çheu-lhiurid as she ${\displaystyle n}$ earroo ny çheughyn.
Yl-lhiatteeane erbee (jannoo ymmyd jeh towse keim)	${\displaystyle {\frac {ns^{2}}{4\cdot \tan(180^{\circ }/n)}}\,\!}$	She ${\displaystyle s}$ y çheu-lhiurid as she ${\displaystyle n}$ earroo ny çheughyn.
Kiare-chuilleig	${\displaystyle lw\,\!}$	She ${\displaystyle l}$ as ${\displaystyle w}$ lhiuridyn jeh çheughyn ny kiare-chuilleig (lhiurid as lheead).
Coheeyntane (dy cadjin)	${\displaystyle bh\,\!}$	She ${\displaystyle b}$ as ${\displaystyle h}$ lhiurid y vun as lhiurid yn yrjid jeeraghan, er lheh.
Rhombus	${\displaystyle {\frac {1}{2}}ab}$	She ${\displaystyle a}$ as ${\displaystyle b}$ lhiuridyn daa hessen y rhombus.
Troorane	${\displaystyle {\frac {1}{2}}bh\,\!}$	She ${\displaystyle b}$ as ${\displaystyle h}$ bun as yrjid (towsit ayns jeeraghan rish y vun), er lheh.
Troorane	${\displaystyle {\frac {1}{2}}ab\sin(C)\,\!}$	She ${\displaystyle a}$ as ${\displaystyle b}$ daa çheu erbee, as she ${\displaystyle C}$ yn uillin eddyr oc.
Kiarkyl	${\displaystyle \pi r^{2}\ {\text{ny}}\ {\frac {\pi d^{2}}{4}}\,\!}$	She ${\displaystyle r}$ y chraue raadeeoil as she ${\displaystyle d}$ y crantessen.
Eelips	${\displaystyle \pi ab\,\!}$	She ${\displaystyle a}$ as ${\displaystyle b}$ ny h-essylyssyn lieh-vooar as lieh-veg, er mod.
Far-voayrdeen	${\displaystyle {\frac {1}{2}}(a+b)h\,\!}$	She ${\displaystyle a}$ as ${\displaystyle b}$ ny çheughyn coheeynt as she ${\displaystyle h}$ y foddeeaght (yrjid) eddyr ny colinnaghyn.
Slane eaghtyr y Rollian	${\displaystyle 2\pi r^{2}+2\pi rh\,\!}$	She ${\displaystyle r}$ as ${\displaystyle h}$ y chraue raadeeoil as yn yrjid, er mod.
Eaghtyr lhiattagh y rollian	${\displaystyle 2\pi rh\,\!}$	She ${\displaystyle r}$ as ${\displaystyle h}$ y chraue raadeeoil as yn yrjid, er mod.
Slane eaghtyr y chughlin	${\displaystyle \pi r(l+r)\,\!}$	She ${\displaystyle r}$ as ${\displaystyle l}$ y chraue raadeeoil as yn yrjid sceau, er mod.
Eaghtyr lhiattagh y chughlin.	${\displaystyle \pi rl\,\!}$	She ${\displaystyle r}$ as ${\displaystyle l}$ y chraue raadeeoil as yn yrjid sceau, er mod.
Slane eaghtyr ny cruinney	${\displaystyle 4\pi r^{2}\ {\text{ny}}\ \pi d^{2}\,\!}$	She ${\displaystyle r}$ and ${\displaystyle d}$ are the radius and diameter, respectively.
Slane eaghtyr yn eelipsoyd		Jeeagh er yn art.
Rheynnag chiarkylagh	${\displaystyle {\frac {1}{2}}r^{2}\theta \,\!}$	She ${\displaystyle r}$ as ${\displaystyle \theta }$ y chraue raadeeoil as yn uillin (ayns raadjanyn), er mod.
Çhyndaays eaghtyr kerrinagh dys eaghtyr kiarkylagh	${\displaystyle {\frac {4}{\pi }}A\,\!}$	She ${\displaystyle A}$ eaghtyr y cherrin ayns unnidyn kerrinagh.
Çhyndaays eaghtyr kiarkylagh dys eaghtyr kerrinagh	${\displaystyle {\frac {1}{4}}C\pi \,\!}$	She ${\displaystyle C}$ eaghtyr y chiarkyl ayns unnidyn kiarkylagh.

Ta ny calghoolyssyn shoh heose taishbyney c'red eaghtyr ram cummaghyn cadjin y gheddyn.

She bun ta'n art shoh. Cur rish, son foays y yannoo da Wikipedia.