解：??$(1)$??點(diǎn)??$B$??
??$(2)$??對(duì)應(yīng)頂點(diǎn)：點(diǎn)??$A$??和點(diǎn)??$A'$??，點(diǎn)??$B$??與點(diǎn)??$B$??'，點(diǎn)??$C$??與點(diǎn)??$C'$??
對(duì)應(yīng)邊：??$AB$??與??$A'B$??，??$BC$??與??$BC'$??，??$AC$??與??$A'C'$??
??$(3)$??旋轉(zhuǎn)角為??$∠ABA'$??
??$(4)△ABA'$??和??$△CBC'$??都是等邊三角形
由旋轉(zhuǎn)可知：??$AB=A'B$??，??$∠ABA'=60°$??
∴??$△ABA'$??是等邊三角形
同理可得：??$△CBC'$??也是等邊三角形
