An equilateral triangle is one with three sides of equal lengths and three angles (corners) all 60-degrees. It’s really simple to cut and sew rows of equilateral triangles together quickly (and accurately) on your sewing machine. Jeni Baker shows us how in her foolproof guide…
This tutorial was first featured in issue 1 of Love Patchwork and Quilting magazine. If you like fun quilting tutorials involving triangles, you might also like our complete guide to Flying Geese Quilts.
How to cut 60 degree triangles
You can measure and cut triangles quickly and easily with a quilting ruler.
Cut a strip of fabric the width of the height of your triangles. For the Trios Lap Quilt this is 3½in.
Place your ruler on the fabric strip with the 60-degree line along the top edge of the fabric strip. The cutting edge of the ruler will be at a 60-degree angle.
Cut along this line. Discard the end piece of fabric.
Mark your fabric strip at intervals to mark the width of the triangle – for the Trios Lap Quilt this is 4in. Move the ruler so that the other 60-degree line is along the bottom edge of the fabric strip and line it up with the 4in mark on the bottom of the strip. If measured correctly, the ruler will intersect your previous cut to form an equilateral triangle.
Make the cut – this is your first triangle.
Move the ruler again so that 60-degree line is along the top edge of the fabric strip again, this time lining it up with the 4in mark on the top of the strip. Make the cut – this is your second equilateral triangle. Continue like this all the way along the strip, alternating the ruler position with each cut to make as many triangles as the fabric will allow.
How to sew triangles
Now you’ve cut a batch of triangles from your fabric, it’s time to sew them together. Here’s how…
Take two equilateral triangles, one print fabric and one solid.
Using a scant ¼in seam allowance, sew along the right-hand side of the triangles.
Place the next print triangle on the pieced unit, right sides together and aligned at the top unstitched edge, and then sew along the right-hand side.
Open the piece and press the seam open.
For the second row, start with a solid triangle. Repeat steps 1–3 to piece this row.
Place the triangle rows right sides together, lining up the seam and row edges.
Sew the rows together using a scant ¼in seam allowance.