Today involved a great deal of running. I don't mind running but I am not a big fan of doubling back. Instead of running the 400 twice to make an 800, I decided to run around the block that loops behind the building. I thought that it would be close enough to 800. It also had the added bonus of more shade. I looked up a few of loops on Google maps when I got home. This is what I came up with:
The green line is 1032 meters, or just a bit over 1 k (32 meters).
The red line (my sub for 800 meters today) is 973 meters.
The blue line is 1.04 miles.