i. Let A (x1, y1) = A (-7, 6),
B (x2, y2) = B (2, -2),
C (x3, y3) = C(8, 5)
∴ By centroid formula,
∴ The co-ordinates of the centroid are (1, 3).
ii. Let A (x1, y1) = A (3, -5),
B (x2, y2) = B (4, 3),
C(x3, y3) = C(11, -4)
∴ By centroid formula,
∴ The co-ordinates of the centroid are (6, -2).
iii. Let A (x1, y1) = A (4, 7),
B (x2, y2) = B (8, 4),
C (x3, y3) = C(7, 11)
∴ By centroid formula,
∴ The co-ordinates of the centroid are (19/3, 22/3)