This corner-to-corner granny triangle is similar to the granny square one but with a little twist
which differentiate the square from the rectangle, very easy once you understand how it works
and pretty project to add to your crochet knowledge. You can control how big or small you want
the rectangle to be by controlling the number of rows initially done as a triangle. The video
tutorial will help you further. Measurements/ Gauge
18 rows: 32/ 15 cm
10 cm: 18 sts/ 5 rows