Distributing objects spaces them evenly within the area bounded by the current selection. The selected objects can be spaced evenly across or down, or arranged in rows and columns. When you distribute objects in the current selection area, the objects are spaced evenly between the leftmost and rightmost edges of the objects in the selection area.
Livecycle align size.55.6.1 To distribute objects
Livecycle align size.55.6.2 To distribute objects
When you distribute a number of objects in rows and columns, the objects closest to the outer edges of the selection area determine the positions of the leftmost and rightmost columns and the top and bottom rows.
Livecycle align size.55.6.3 To distribute objects
Livecycle align size.55.6.4 To distribute objects
Tip:
For complex layouts, distributing a single row or column at a time provides more control than distributing all of the objects in rows and columns at once. For the best results, you could try distributing the leftmost column first, followed by the topmost row. Afterward, select and left align each row with the leftmost column.
See also 

To distribute objects