a²-b²=√3bc
sinC=2√3sinB→2R*sinC=2R*2√3sinB→c=2√3b→c²=2√3bc
cosA=(b²+c²-a²)/(2bc)
=(c²-(a²-b²))/(2bc)
=(2√3bc-√3bc)/(2bc)
=√3/2
所以A=π/6
a²-b²=√3bc
sinC=2√3sinB→2R*sinC=2R*2√3sinB→c=2√3b→c²=2√3bc
cosA=(b²+c²-a²)/(2bc)
=(c²-(a²-b²))/(2bc)
=(2√3bc-√3bc)/(2bc)
=√3/2
所以A=π/6