Let our points of parallelogram be A(-2, -1), B(1, 0), C(4, 3) and D(1, 2) and mid point of diagonals be E(x,y)

We know that diagonals of parallelogram bisect each other.
Hence,
we find mid point of AC.
By midpoint formula,
x = \(\frac{x_1 + x_2}2\), y = \(\frac{y_1 + y_2}2\)
For point E(x, y)
x1 = \(\frac{-2 + 4}2\) , y1 = \(\frac{-1 + 3}2\)
∴ x1 = \(\frac{2 }2\) , y1 = \(\frac{2 }2\)
∴ E (x, y) ≡ (1, 1 )