You are likely familiar with the method where you'd cut a 2 1/2" square, place it over the corner of the patch where you want the little triangle, sew diagonally across the little square, flip, press and trim the underside waste triangle(s).
If you don't like the little waste triangle there's a way to avoid making them. You need to cut the two patches of course, but you will cut them exactly how you see them plus seam allowances. It's easy enough if you can sew a quilter's 1/4" seam.
Instead of cutting the little squares to sew and flip ( usually 2 1/2" squares") you will cut triangles.Pick your favorite way. 2 7/8" squares cut once diagonally or an Eazy Angle Type ruler on a 2 1/2" strip.
Then to cut your larger patch, cut the base shape the measurement given in the pattern. Then trim the corner (where that square would have been stitched) before sewing on the triangle. In this example, trim a triangle 2 1/8" tall, measured on the short edge. I don't have all the triangle rules so I am not sure what line you'd use, so measure your tool. My Easy Angle ruler and the Omnigrid ruler are at Studio 3. I can measure them tonight and edit this.
On Judy Martin's Ultimate S45 ruler,use the 2 1/8" line.
And I can tell you on this Creative Grids 45 triangle ruler, use the 1 3/4" line.
There is a ruler that has these trimming templates printed on it in various sizes. It's the Rotary Mate ruler by Trudie Hughes. Contact PatchedWorks.com.
Hope this helps.