Originally Posted by
cjsews
You can also draw your line from corner to corner and stitch 1/4 inch on each side.
Right ... or place the 1/4" measurement on the center line then draw you're left line, turn the ruler and place 1/4" measurement on the center line and draw the opposite line. In short .. you really don't need to draw three lines.
As the others said though, cutting first and sewing second leaves a large chance that you will distort the pieces because you will have a raw bias edge.