prallelogram abcd with vertices A(6,8) b(10,9) c(9,3) d(5,2) 90° counterclockwise rotation about p(4,1)

Given the vertices of parallelogram ABCD:
A(6, 8), B(10, 9), C(9, 3), D(5, 4)
Center of rotation P(4, 1)
After a rotation of 90 degrees counterclockwise, the coordinates (x, y) changes to (-y, x).
(x, y) ==> (-y, x)