view coordinates second point cursor than the first point: how?

[reggio]

hi to all, I would like to know if and how it is possible to display in the bottom left (zone x) the coordinates of the second point "b" relative to the starting point "a".

as in the example of the image, drawing a rectangle, I would like to see the coordinates of "b", not compared to the origin, but compared to the first point "a".
is it possible in autocad2011?
Would you explain how?

 

[Cristallo]

you can do it through dynamic input (f12)
normally gives it in polar coordinates, but if you go to the setting you can set it in Cartesian coordinates.

the coordinates will see them near the cursor

 

[reggio]

Grazie!!!

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