[질문] acosA=bcosB일때무슨 삼각형인가요 증명방법

acosA=bcosB는,sin법칙에의해서a=sin A*2R,b=sin B*2R이나오는것을대입해보면,sin A*2RcosA=sin B*2RcosB와sin A*2cosA=sin B*RcosB로,각C가직각인Δ거나A=B인Δ