Question

Show that the points (0, -1), (-2, 3), (6, 7) and (8, 3) are the vertices of a rectangle

Answer 1

given 
let the points be A,B,C,D.
distance between points under root (x2-x1) whole square+(y2-y1)whole square
so distance of AB=under root 20
distance of BC=       " "           80
"          "       CD=     "  "           20
"         "         DA=    "  "           80 
THAT MEANS THAT opp sides are equal  then diagonals must also be equal then
AC=10 and BD=10 as diagonals and opp sides are equal they are vertices of rectangle