设△ABC的内角A，B，C所对边的长分别为a，b，c，若b+c=2a，3sinA=5sinB,则角C=(A)π... 问题详情：设△ABC的内角A，B，C所对边的长分别为a，b，c，若b+c=2a，3sinA=5sinB,则角C=(A)π/3 (B)2π/3(C)3π/4 ...
