Birman, Graciela S.; Nomizu, Katsumi Trigonometry in Lorentzian geometry. (English) Zbl 0555.51009 Am. Math. Mon. 91, 543-549 (1984). This is a short introduction to the topic given in the title. Main tool is the so-called reversed Cauchy-Schwarz inequality for certain vectors in vector spaces with an indefinite metric. Reviewer: Bernd Wegner Cited in 2 ReviewsCited in 36 Documents MSC: 51M05 Euclidean geometries (general) and generalizations 51-01 Introductory exposition (textbooks, tutorial papers, etc.) pertaining to geometry Keywords:Euclidean geometry; trigonometry; Lorentzian geometry; reversed Cauchy- Schwarz inequality PDFBibTeX XMLCite \textit{G. S. Birman} and \textit{K. Nomizu}, Am. Math. Mon. 91, 543--549 (1984; Zbl 0555.51009) Full Text: DOI