After squares, triangles are easily the most used geometric shapes in patchwork quilts.  More specifically, it is the right angle triangle – the half-square triangle – that quilters treasure.  This particular triangle has two sides of equal length, two interior angles of 45°, and a third interior angle of 90° (the right angle).  A right angle triangle doesn’t necessarily have two sides of equal length, but a half-square triangle must.  Otherwise, two triangles together wouldn’t make a square!  This also means it is an isosceles triangle.

One of the first quilts that I ever made – the first quilt, I believe, that I finished – was made from a block of squares and half-square triangles.  The quilt, called Cabin Lights, was pictured on the cover of the first issue of Quiltmaker magazine that I ever bought (which must have been sometime in 1994).  The design is created by the position of light and dark color values.  It was presented in the magazine as a scrap quilt but since I didn’t have any scraps yet, I had to buy all the light and dark blue fabrics that I used in the quilt.  I called my quilt “Miles To Go Before I Sleep”, because the wintry trees in the border fabric reminded me of Robert Frost’s poem Stopping by Woods on a Snowy Evening.

There are so many blocks made entirely from half-square triangles, it is hard to decide which ones to feature.  So let’s choose from some of the quilts I have made.  This first block is an old classic called “Corn and Beans”.  Where the four blocks came together in the middle, I replaced some of the smaller triangles with a large one to create space for the appliqué.  A pieced border echoes the shapes formed by the blocks.  The result is a 24-½” square wall quilt called Great is Thy Faithfulness.

Another block made entirely from half-square triangles – with a name near and dear to my heart – is Lady of the Lake.  Again, I modified the block by replacing some of the small triangles so that four blocks together would have open background space.  In this space, I appliquéd cottage-themed sewflakes – papercut appliqué designs.

I discovered something interesting while I was designing this quilt.  When two sets of half-square triangles came together along the outer edges of the Lady of the Lake blocks, they formed a flying geese unit.  This is how I ultimately constructed the quilt, also adding a border of half-square triangles to complete the flying geese around the outside edges.

The entire quilt measures 64″ square and is called Be Still.

This final example was chosen because it illustrates a less traditional use of half-square triangles.  The blocks were made using Paula Nadelstern’s simple symmetry technique.  Four half-square triangles were cut from the exact same location in symmetrical fabric as well as four mirror-images of those triangles.  When the eight triangles were sewn together, beautiful kaleidoscopic images were formed.  In this case, the triangles are just the tool that was used to create shapes that are anything but geometric.  I’d say, based on our categories of shapes, the kaleidoscopic images are non-objective or maybe even accidental.

Believe it or not, I have more to say about triangles!  This is because half-square triangles, while predominant, are not the only kind of triangles used in quilts.  Next week, we’ll look at equilateral, scalene, acute and obtuse triangles to discover what amazing effects they can produce in quilt design.