I know how to chain stitch, I did it on the first part of this. But I'm having a complete blank. I showed this last year but it became a UFO because the wind blew it off my wall. I have one simple project before this, but I'm stuck thinking about ths. I can't picture it in my head.
Click image for larger version. 

Name:	tri2.jpg 
Views:	41 
Size:	105.8 KB 
ID:	64453