∵（A-B）+（B-C）=A-C=2根号3
（A-B)^2+（A-C)^2+(B-C)^2
=A^2+B^2-2AB+A^2+C^2-2AC+B^2+C^2-2BC
=2A^2+2B^2+2C^2-2AB-2AC-2BC
=2(A^2+B^2+C^2-AB-AC-BC)
=(根号3+根号2）^2+（根号3-根号2）^2+（2根号3）^2
=3+2+2根号6+3+2-2根号6+12
=22
∴A^2+B^2+C^2-AB-AC-BC=11