已知四边形ABCD的顶点为A(m,n),B(6.1),C(3.3),D(2.5),求m,n的值,使四边形ABCD的直角梯

AB//DC
AB(6-M,1-N )
DC(1.-2)
(6-M)X(-2)=(1-N)X1
2M-12=1-N
2M=13-N

AD(2-M,5-N)垂直DC(1,-2) 2-M+2N-10=0 M=2N-8
2(2N-8)=13-N
4N-16=13-N
N=29/5,M=18/5