MathDB
Trigonometry and Triangles

Source:

August 11, 2019
trigonometry

Problem Statement

How many distinct triangles ABCABC are tjere, up to simplilarity, such that the magnitudes of the angles A,BA, B and CC in degrees are positive integers and satisfy
cosAcosB+sinAsinBsinkC=1\cos{A}\cos{B} + \sin{A}\sin{B}\sin{kC} = 1
for some positive integer kk, where kCkC does not exceet 360360^{\circ}?