Triangle Problem
Geometry
Level
4
In triangle \( ABC \), \( \cos A : \cos B : \cos C = 2 : 9 : 12. \)
If \( \sin A : \sin B : \sin C = p : q : r \), where \( p \), \( q \) and \( r \) are coprime positive integers, find the value of \( pqr-(p+q+r). \)
by
Hugh Sirakarn