Answer:
A'(-1, 1), B'(-2, 1), C'(-2, 2) and D'(-1, 3).
Step-by-step explanation:
Transformation is the movement of a point from its initial location to a new location. Types of transformation is reflection, rotation, translation and dilation.
Rotation is the turning of an object about a point. If a point A(x, y) is rotated 90 degrees counterclockwise about the origin, the new point would be A'(-y, x)
From the image attached, the coordinates of polygon ABCD is A(1, 1), B(1, 2), C(2, 2), D(3, 1). If polygon ABCD is rotated 90 degrees counterclockwise about the origin, the new vertices would be at A'(-1, 1), B'(-2, 1), C'(-2, 2) and D'(-1, 3).