Consider the point A(-1,2), B(6,2) and C(1,-20) in the plane. For how many different points D in the plane are A, B, C and D the vertices of Parallelogram?

Consider the point A(-1,2), B(6,2) and C(1,-20) in the plane. For how many different points D in the plane are A, B, C and D the vertices of Parallelogram?

Explanation
Consider the point A(-1,2), B(6,2) and C(1,-20) in the plane. Three different points D in the plane are A, B, C and D the vertices of Parallelogram.