Oh that's pretty obvious, 15 degrees, 360 and 180 degrees. I actually thought of using some other number for the number of degrees, but it turns out that 360 is a kick ass number. Seriously, it is awesome. So the problem is not that... I was more refering to the numerals and maths themselves. Here's a hint: the "5" looking shape is actually a numeral meaning 3.
Seriously, it's quite complicated. You don't even have that much information to go on! Possibly impossible to figure out.
This is a fantasy map, so it doesn't have a modern setting. Tech-level around 17th century, some more, some less, and a bunch of magic to compensate, etc. I'm trying to go for a bit more fantastical instead of mechanical fantasy, but it's hard. Have to keep on reminding myself that people in the past don't think like I do, etc.