Assertion: triangle's angle | /r/HasAspect | rational cosine
Facets:
value: by the law of cosines
type: OTHER
value: for integer triangles
type: OTHER
Source sentences:
text: Every angle of a Heronian triangle has a rational cosine.
text: For integer triangles the remaining angles must also have rational cosines and a method of generating such triangles is given below.
text: Every angle of a Heronian triangle has a rational sine.
text: By the law of cosines, every angle of an integer triangle has a rational cosine.
text: But all the angles of integer triangles must have rational cosines and this will occur only when ​p⁄ q = ​1⁄ 3 :p.2