The points (5, - 4,2),(4,- 3, 1),(7, - 6, 4) and (8, - 7 , 5) are the vertices of
Let , A(5, -4,2), B(4, - 3, 1), C(7, -6, 4) and D(8, - 7 ,5).
Then,
Here, we see that opposite sides .AB = CD,BC = AD are equal and diagonals
Hence, given points are the vertices of a parallelogram.