△ABC中,abc分别是角A角B角C对边边长,已知abc成等比,且a^2-c^2=ac-bc,求角A及bsinB/c

cosA=(b^2+c^2-a^2)/2bc
=(ac+c^2-a^2)/2bc
=bc/2bc=1/2,A=60度
a/sinA=b/sinB
sinB=bsinA/a
bsinB/c=b^2sinA/ac=b^2sinA/b^2=sinA=0.5