"以规定距离排列的" can be translated into English as "arranged at a specified/prescribed distance" or "spaced at a regulated/fixed interval" depending on the context.
For example:
The trees are arranged at a specified distance from each other. （树木以规定的距离相互排列。）
The components are spaced at a regulated interval on the circuit board. （电路板上的元件以规定的间隔排列。）