The half square triangle unit is probably the most commonly used patch in a quilt block -- well it is second only to the square. It is made simply with two triangles, filling up half the square each -- hence the name. Take a quick look through this website, or in any quilting magazine, and you will start to notice that this half square triangle, regardless of its size, is present in more quilts than not.
Free Quilt Block Pattern
The Pall Mall quilt block is a four patch that is a good choice for the beginner quilter. It contains only simple shapes -- squares and half square triangles. However, don't let the fact that this is a simple block to make, as it can be quite effective when used in your quilt.
The sample quilts illustrated show two different styles of settings -- the side by side layout (with sashing) as well as an on point style. By adding extra blank blocks you can extend the size of your quilt and show off your quilting skills as well.