Crumby Sunday

I kept going with the crumb blocks today because I was having so much fun. I just kept sewing scraps on randomly from the brights bin until I got to about 7 inches and then squared everything up at the end. Whatever I chopped off went back into the bin to be recycled. No plan, no measuring, just mindless chain sewing. The bin is pretty empty now, so I'll move onto the muted colors bin next. 36 blocks done, all from scraps most people would have thrown away (insert maniacal laugh here).
I was thinking of doing a diagonal set and offsetting the rows to get a zig zag effect. I tried it once before but did bad math and ended up lobbing off all the points. Maybe Amy can help me with the math. How big do I need to cut the setting triangles to go with 7 inch blocks? I'm testing the "red is a neutral" hypothesis. I didn't have much for reds, so I also pulled out a pink, an orange and a yellow as well. I'm having trouble deciding, what you y'all think?