Question 1178013
Let the vertices of a rhombus are A(1,2), B(2,-5), C(7,0) and D(p,q)
.

We know that diagonals of rhombus bisect each other,

∴  Co-ordinates of mid-points of AC= Co-ordinates of mid-points of BD


mid point of AC = (1+7)/2 , (2+0)/2
(4,1)

Mid point of BD = (p+2)/2 ,(q-5)/2


4=(p+2)/2
p+2=8
p=6

(q-5)/2=1
q=7

D~ (6,7)