(1)设D(x,y),
则
AC =(-1,1) ,
BD =(x-2,y-3) ;
由
AC =
BD ,
解得x=1,y=4.
所以D(1,4).
(2)由(1)得
AD =(2,6) ,
BC =(-4,-4) ;
所以 |
AD |=2
10 , |
BC |=4
2 .
(1)设D(x,y),
则
AC =(-1,1) ,
BD =(x-2,y-3) ;
由
AC =
BD ,
解得x=1,y=4.
所以D(1,4).
(2)由(1)得
AD =(2,6) ,
BC =(-4,-4) ;
所以 |
AD |=2
10 , |
BC |=4
2 .