isosceles (adj.)youdaoicibaDictYouDict[isosceles 词源字典]
"having two equal sides," 1550s, from Late Latin isosceles, from Greek isoskeles "with equal sides," from isos "equal" (see iso-) + skelos "leg," from PIE *skel-es-, from root *(s)kel- (3) "crooked" (see scoliosis).[isosceles etymology, isosceles origin, 英语词源]