Sunday 2 December 2012

How to cut equilateral triangles - a tutorial

As you'll know if you're a regular reader, I have cut and sewed quite a lot of equilateral triangles lately. The first lot were for the quilt I am making for one of my brothers (pictures of the finished top here), and the second lot (and I mean a lot) were for my Oakshott quilt.

In case anyone else is interested in making an equilateral triangle quilt, I thought I would put together a quick tutorial on how to cut them.  They're not difficult at all!

First method - equilateral triangle ruler

There are a variety of equilateral (or sixty degree) triangle rulers out there.  I use the 3-9 inch one by Marti Michell, which gives finished sides of between 3 inches and 9 inches.  I like the one I have, but I'm sure they're all fine.

First, you need to cut a strip of fabric, making it as wide as desired for the size of triangles you are making.  Then, line your ruler up with the bottom edge of the fabric, and trim the first corner off.

I now like to flip the fabric round so that the angled end is on the left, because I am right handed.  Then,    line your ruler up with the top edge of the fabric, and cut your first triangle.

Some equilateral triangle rulers (like this one) have the corners snipped off, so that you can use them to trim the corners off your fabric triangles.  If the ruler you are using has that option, I highly recommend you take it!  If it doesn't don't worry, I will show you how to do it using an alternative method below.

Just line it up, a little slice, and...

voila, your corner is trimmed.  Repeat for the other corner, and you have your first piece, ready to sew.

Second method - standard ruler

There is no real need to go out and buy a fancy ruler for equilateral triangles.  It might be helpful if you are making lots, but it is entirely possible with most standard quilting rulers.

Find the sixty degree line on your ruler, and line it up with the bottom (or the top, depending on which way you are cutting) of your fabric.

Cut along that line.

Now, trim up corners.  All you need to do is line one edge of the triangle up with a line on your cutting mat so that the triangle is pointing to the left.  Line your ruler up so that the point hits the quarter inch line.  Now trim along that line.  Repeat for each corner, and you will have a perfect piece ready to sew. Easy peasy!

Hopefully this is helpful - please let me know if you have any questions!  Also, thanks to my sister, whose hands appear in this tutorial.

If you've used this tutorial to cut equilateral triangles, you might also find my tutorial on how to sew equilateral triangles helpful!

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Susan said...

I love equilateral triangles! Do you have any clues about lining them up for sewing?

Catherine said...

Thanks for such a handy tutorial - I think I'm going to have to ask for some nice rulers for Christmas now:-)

Rebecca said...

Thank you! I just used this. :)

liniecat said...

I found thids really helpful...........many quilt blog hopping lol

Karee said...

As the fabrics are stacked (right after cutting) I draw a quick line on the tip that is on grain. Marking the grain tip keeps your triangles lined up correctly so you are mixing bias with straight of grain. Does that make sense? Bias to bias, keeping grain at top and tip.