The Collaborative International Dictionary
Isoperimetrical
Isoperimetrical \I`so*per`i*met"ric*al\, a. [Gr. ?; ? equal + ? circumference: cf. F. isop['e]rim[`e]tre. See Perimeter.] (Geom.) Having equal perimeters of circumferences; as, isoperimetrical figures or bodies.
Wiktionary
isoperimetrical
a. isoperimetric