Question

if there are four points P(2,-1) ,Q(3,4) ,R(-2,3) and S(-3,-2) in a plane ,then prove that PQRS is not a square but a rhombus .

Answer 1

it can be proven by
firstly we should prove all sides are equal
it can be done by distance formula
then after that we need to show that all angles are perpendicular to each other