use col; 
arrows use text.size.normal=10;
a, b, c [width=100, margin=20]; 
b [width=20];
use label.pos=right;  
b@ne->a: ne; 
b@e->a@ne: e;
b@170->c: 170 degrees;
use label.pos=left;  
b@-20->a: -20\ndegrees [label.align=30];
