Let P(4,6), Q(7,10) and R(-1,2) be the given points.
∴ Area of ∆PQR = 1/2 [4(10 - 2) + 7(2 - 6) - (-1)(6 - 10)]
=1/2 [32 - 28 + 4] = 4 sq. units
Now shifting (x, y) to (X - 2, Y + 1)
New coordinates are X = x + 2, Y = y - 1
∴ P(4,6) → (6,5)
Q(7,10) → (9,9)
R(-1,2) → (1,1)
∴ Area of ∆ = 1/2 [6(9 - 1) + 9(1 - 5) + 1(5 - 9)]
= 1/2 [48 - 36 - 4] = 4 sq. units
Hence, the area remains invariant.