What theorem about a triangle's 9-Point Circle is dynamically being illustrated below?[br](Feel free to move the triangle's vertices anywhere you'd like!)
[b]Theorem:[br][/b][br]Of the 9 points in a triangle's 9-Point Circle, 6 of these points serve as vertices of 3 unique rectangles. These points are the midpoints of the sides of the triangle (there are 3 such points) AND the midpoints of the segments connecting the triangle's [color=#ff7700][b]orthocenter [/b][/color]to each vertex (there are 3 such points).