问题
填空题
在△ABC中,若
|
答案
=BC
-AC AB
∴|
|2=BC
×BC
=(BC
-AC
)AB BC
=
•AC
-BC
•AB BC
=1-(-2)
=3
∴|
|=BC 3
故答案为:3
在△ABC中,若
|
=BC
-AC AB
∴|
|2=BC
×BC
=(BC
-AC
)AB BC
=
•AC
-BC
•AB BC
=1-(-2)
=3
∴|
|=BC 3
故答案为:3