Petersen-Morley theorem

English Etymology Named after Johannes Trolle Petersen (later Johannes Hjelmslev) and Frank Morley. Proper noun 1 en geometry A theorem stating that, if a, b, c are three general skew lines in space, if a′, b′, c′ are the lines of shortest distance respectively for the pairs (b,c), (c,a) and (a,b), and if p, q and r are the lines of shortest distance respectively for the pairs (a,a′), (b,b′) and (c,c′), then there is a single line meeting at right angles all of p, q, and r. en eponyms