- Whenever 2 lines of equal lengths intersect at their mid-points ,
- the 4 end-points of the 2 lines will form the 4 nodal-points for a rectangle .
And in the special case of the 2 Lines intersecting at an angle of 90 degrees ,
- the 4 end-points of the 2 lines will form the 4 nodal-points for a square .

- Let us now focus our attention on the diagram on-the-right , above .
And we see here that :
- we can join the mid-points of each pair of [ opposite sides ] of the rectangle ,
- to come up with two (2) new lines passing thru the original point-of-intersection .
And we take note immediately that the 2 new lines do intersect at an angle of [ 90 degrees ] .
- And , in preparation for our discussion to follow in the next 2 Section :
- we shall always mark-off the longer of the 2 new lines in [ red-color ] and name it the [ red-color line ] ;
and
- we shall also mark-off the shorter of the 2 new lines in [ blue-color ] and name it the [ blue-color line ] ;
Additionally , we shall refer to the [ cross ] formed by the 2 new lines as the [ Red-And-Blue Cross ] .