a,b,c为△ABC的三边,且3a^3+6a^2b-3a^2c-6abc=0,则 △ABC的形状为____

问题描述:

a,b,c为△ABC的三边,且3a^3+6a^2b-3a^2c-6abc=0,则 △ABC的形状为____

3a^3+6a^2b-3a^2c-6abc=0,
3a^3-3a^2c+6a^2b-6abc=0,
3a^2(a-c)+6ab(a-c)=0
a-c=0
a=c