Saturday, August 20, 2011

Triangle in a square - tutorial

Hi everyone,

I've been  working on my blocks for the Broken Dishes QAL.

In the border of the pattern I drew up,
there is a triangle in a square block.
As I had mentioned in the first post of this quilt-a-long,
I want you all to make this quilt in any size you want.

Sew I need to teach you how to make the triangle in a square block any size you want too!!!

Here we go.

First decide what size your finished block will be.
(Note: this is the size of your original HST block.)

I'm making a 4 inch finished block.

Grab your graph paper and draw a square the size of your finished block. 
Mine is a 4 inch square.
On the top of your square, find the middle and mark the spot.
 Mine is 2 inches. 
Draw a line from this spot to the bottom left corner of the square,
then draw a line to the bottom right corner of the square.
See picture below.
You will now draw a 1/4 inch seam all around your square.

You will use your paper scissors and cut out your template 1/4 bigger than that.
So, your cutting out a 5 inch paper template.
Make 4 templates.
Chose the fabric to make the triangle.
Cut 4 squares the same size as your paper template.
So, I cut a 5 inch square.

Chose your background fabric.
I cut a piece from a coordinating fat quarter.
I came up with a formula to know how big a rectangle you need to cut for this to work.
a = width of rectangle
b = length of rectangle
a = 1 inch + half the width of your finished square
In this case, a= (1+2) 3 inches
b = 2 inches + the size of your finished square.
In this case, b= (2+4) 6 inches

Therefore, you will cut 2 rectangles 3 inch X 6 inches from your background fabric.

I hope I'm not confusing you here.

Lay your square right side down.
Put your paper template right side up over your fabric square.
Pin your paper template to your fabric square.

Take your background rectangles and lay it right side together over your triangle fabric as in picture below.
You will bring these two pieces up to the light and adjust the position of the background fabric.
Make sure that you leave enough fabric at the top sticking up, so that when you iron your background fabric back it will cover the whole corner.
Now, without moving the pieces, bring it over to the sewing machine.
Make sure that you reduce the stitch size on your machine.
Then stitch on the line as shown below.
Bring your stitched piece to your ironing board and iron the background fabric back.

You will them trim the triangle fabric that is behind the background fabric.
See picture below.

This is what it will look like from the paper side, once you've trimmed the triangle fabric.
(I know I did #3 before 2. It doesn't really matter for this block which side you do first)
Now, do the same for the other side.
When I sew the second piece of background fabric, I like to start stitching in the seam allowance.
It just makes the point of your triangle look that much better.
See below.
Make sure you trim the triangle fabric on the other side too.
Now, take your squaring ruler and cut on the paper side to square your block.
See pictures below.

And you are done!!!
It's perfect!!!

You can now make your own Triangle in a square block any size you want.

I made a 6 inch finished block, and 3 inch finished block the exact same way to ensure that my math worked for all sizes.

Make your paper template the same way.

Cutting for the 6 inch finished block is:
Paper template should be 7 inches square
Triangle fabric - cut a 7 inch square
Background fabric - cut 2 rectangles 4 X 8 inches

Cutting for 4 inch finished block is:
Paper template should be 5 inches square
Triangle fabric - cut a 5 inch square
Background fabric - cut 2 rectangles 3 X 6 inches

Cutting for 3 inch finished block is:
Paper template should be 4 inches square
Triangle fabric- cut a 4 inch square
Background fabric - cut 2 rectangles 2.5 X 5 inches

I hope this helps all of you.
You will need 4 of these blocks for the border of your Broken Dishes Quilt.


36th Avenue


Kristi said...

Wonderful tutorial!

Impera_Magna said...

Too cool! Thanks for this tutorial, Ariane!!!

Barb said...

Thanks for the tutorial!! It was great!

Michele Pacey said...

I was just reading about foundation piecing and then you did this. Perfect case-in-point refresher Ariane, thanks!

ferne said...

My mind is reeling and trying to figure out where you are going with this and why would we only need 4? My guess is that they are for the corners, but I just can't picture it. I love paper piecing though and I will be doing this!

Jayne said...

Hi! I've enjoyed the great instructions and hints for triangles in your tutorials. I have even referenced them in my upcoming blog post. I thought you'd want to know, and to take a peek.


Linda in Calif. said...


Thank you so much for this tutorial and showing us how you did the math. We will be doing a Little Forest Quilt Along and I would like to use this method to make my little trees. Also, I had one person ask me about a way to keep the trees whole instead of cut up. May I link to your site telling people to come here for your tutorial?

If you have time and like the Little Forest Quilt, we would love for you to come sew with us. The Quilt Along starts Sept 1st.

Dresden Quilter said...

Great tutorial! I would call this teaching, wouldn't you? ;-)

Celine said...

Thanks very much for a very good tutorial. I have followed it for my little tree and it came out perfect. Thanks for sharing it.