Updating Pattern of Prefabs

In the Unity docs is an example of positioning prefabs in a pattern. For example a circle. My question is, what if you want to update the radius of the circle so that the prefabs expand from the center as you drag the mouse. I can set the point of initiation to where I click the mouse and get the distance from that position to current mouse position as I drag to set the radius. But how do I actually update the positions to the new radius? Thanks.

public GameObject prefab;
public int numberOfObjects = 20;
public float radius = 5f;

void Start() {
	for (int i = 0; i < numberOfObjects; i++) {
		float angle = i * Mathf.PI * 2 / numberOfObjects;
		Vector3 pos = new Vector3(Mathf.Cos(angle), 0, Mathf.Sin(angle)) * radius;
		Instantiate(prefab, pos, Quaternion.identity);
	}
}

You should store the prefab instances into a list.

In update event, you should loop the items in that list and update them 1 by 1.