The first step to determine that the rectangle in Quadrant III is congruent to the rectangle in Quadrant I was to rotate the first rectangle 90 degrees clockwise about the origin. Translate by what?

To determine that the rectangle in Quadrant III is congruent to the rectangle in Quadrant I after rotating it 90 degrees clockwise about the origin, the next step would be to translate the rectangle. However, the translation required to make the rectangles congruent depends on the dimensions of the rectangles and their relative positions. Without specific information about the dimensions and positions, it is not possible to determine the exact translation needed.