This video gives proofs of the two Triangle spread rules, which tell us how to choose the third spread of a triangle given two spreads. The arguments are somewhat complicated, involving some rather magical identities. This video is part of the WildTrig series, which introduces Rational Trigonometry and applies it to many different aspects of geometry.
Questions about WT61: Proofs of the Triangle spread rules
Want more info about WT61: Proofs of the Triangle spread rules?
Get free advice from education experts and Noodle community members.