How do I place guy wire anchors the right way?

How do I place guy wire anchors the right way?

In general it is advised to build masts symetrically – for 3 cornered trunks it would be 120 degrees each. Anchors sholud not be closer to the mast than half of its height. For example for a 50 meters high mast, anchors must be at least 25 meters apart from its axis.