Once you have worked the base row of triangles for entrelac, it's time to start shaping what's known as the purl side squares and triangles.
As with the base triangles you're working short rows and will be both knitting and purling, but the decreasing happens on the purl side.
This section starts with a triangle on the left-hand side of the work that will help make the edge straight.
For the purposes of this tutorial, I switched colors here to make it easier to see what's going on; that's also a popular way to knit entrelac, but you can certainly do it all in one color if you prefer.
To begin the side triangle, change to your second color, leaving a long tail when cutting off the first color. Purl the first 2 stitches, then turn the work and knit those same 2 stitches. Turn the work again.
