rectangle in Quadrant III is congruent to the rectangle in Quadrant I was to rotate the first rectangle 90 degrees clockwise about the origin. What is the next step?
The next step would be to determine the coordinates of the vertices of the rotated rectangle. This can be done by applying the rotation matrix:
[x'] [0 1] [x]
[y'] = [-1 0] * [y]
where (x, y) are the coordinates of a vertex in the original rectangle, and (x', y') are the coordinates of the corresponding vertex in the rotated rectangle.