If you want to try going with guides route, one easy way of making a fixed length guide is to start on the origin, then pull out on green and make it the length of your build plate. Now you easily see the cpoint but the tail is hard to see when it's on axis, so just move the guide off axis a bit for visibility. Now array 3 more copies. But since you can't inference to the tails, easier to array in a 2 x 2 grid that is sized to your build plate. Anyway, get the cpoints in place first any way you can, then rotate the tails in place later, just my opinion, there would be 50 ways of doing this. Then make them a group and move the corner back to the origin. Just a thought.