we know that
In a Rhombus all sides are congruent
so
AB=BC=CD=AD
Find the distance AB

The distance formula between two points is equal to




Find the perimeter of a Rhombus
the perimeter of a rhombus is equal to

where d is the length side of the rhombus
in this problem

so


therefore
the answer is
The perimeter of the rhombus is equal to
