I'm working on instructions for tilting a piglet. Here I am reverse engineering the measurements. I sew triangles on the sides to tilt a pig, but this will let me figure out the size of the triangles. And when I made my piglets, I sewed the side triangles on the bias. This made the blocks different sizes and definitely complicated sewing the quilt top.
Here I marked the finished and unfinished size.
Now I can remove and measure the triangles, except oops, the green triangle is cut wrong. It comes off the block too soon. And while I go back and make another demonstration piece, we will consider this a tutorial on measuring twice and cutting once or do as I say, not as I do.