There are lots of shapes of shawls out there. The most common are triangles and rectangles, partly I suspect because they are the easiest to design. But those may not be knitters favorites to wear.
Obviously, different knitters want different shape shawls. This is because they want different things from their shawls. Some want warmth, some want frothy lace, some just want a colorful neck accessory like a scarf. For me, I want a lightweight shawl to cover my arms to keep cold air from fans and A/C from hitting my skin. Thus, I’m going to be looking for different shaped shawls than other knitters.
A lot of knitters say that they don’t like triangular shawls because they don’t want an arrow pointing at their rear end. Others don’t like them because the straight upper edge makes it hard to keep on. I personally don’t like them because I want a shawl to cover my arms and they have to be HUGE before that will happen.
Rectangular shawls or stoles don’t cover very much unless they are very wide and they don’t stay on easily. I’ve never been able to wear one where it actually stayed where I wanted it. It either rode up and looked like a scarf or rode down and was just a ribbon draped between my elbows.
My favorite shapes are crescents (also called heart shaped or triangles with wings). This is the shape of my Silver Bells and Cockle Shells. The wings at the front edge help keep it situated on your shoulders and provide more depth at the sides over your arms. Close contenders are the 3/4 square made of three triangles instead of two and the more than half circle. These also stay on well because they don’t have a straight upper edge and cover my arms. Additional plus is that these shapes don’t have a point above the rear end.
There have been a number of discussions about shawl shapes on Ravelry. In one of the recent discussions, I added a poll so readers could vote for their favorite shawl shapes. The results so far have been surprising. Triangles have very few votes. The shape with the most votes by a landslide has been shallow crescent. Reading all the reasons given has been interesting. If you haven’t voted in that poll yet, please do.