Quilt Making | Quilting

How to Make a Triangle in a Square Block

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Inside: How to Make a Triangle in a Square Block

Do angled blocks scare you? Me, too. I like the design of the Triangle in a Square block, but sewing those angles always seems to be a challenge.

But, that doesn’t have to the case. Today I’m showing you how to simplify this block by using the V Block Ruler. This ruler is a quilting game-changer. Read more and you’ll learn why!

This block is the first in a series of three posts that will be used to make the soon to be revealed Midnight Star Table Topper. 

For now, follow these directions to make eight Triangle in a Square blocks.

How to Make a Triangle in a Square Block

Gather Your Materials

Basic Sewing Supplies Needed


Materials:

How to Make a Triangle in a Square Block

I recommend using a dark blue fabric for your main fabric and a white fabric for the background.

These can have tone on tone colors or they can be solids. But the colors should appear to be dark blue and white when sewn together.

Note: You’ll definitely want to stick to these colors if you want to make a Midnight Star Table Topper project.

Qty. (8) 4-1/2″ square Triangle in a Square blocks to make the Midnight Star Table Topper. To make them using the V Block Ruler from Studio 180, you needed to cut:

  • (1) 5″ wide strip of Dark Blue fabric by the WOF (Width of Fabric)
  • (1) 5″ wide strip of background fabric by the WOF (Width of Fabric)

How to Make a Triangle in a Square Block

Step 1:

To make this block, start with a strip of fabric 1″ wider that the finished size of the block you are making. In this case, we’re making a 4″ finished block, so the strips are 5″ wide.

For the background (white fabric) center triangle, start with part of the background strip folded over on itself. Place the ruler so that the dotted line that says “Fold line for center triangles” along the fold. If you use the solid line, the triangle will be too large. (Ask me how I know.)

The bottom of the strip should match up with the line on the ruler that represents the finished size of the eventual block. In this case it’s the line marked 4″.

Using a rotary cutter, cut on the slanted edge of the ruler.

How to Make a Triangle in a Square Block

Step 2:

Flip the fabric so the angle you just cut is in the opposite direction. Align the angled cutting line on the ruler (left) with that angle and cut along the angled edge (right) of the ruler.

You now have two triangles! Continue this process until you have made all eight triangles that are needed for this project.

How to Make a Triangle in a Square Block

Step 3:

Making the side triangles (dark blue fabric) is a little trickier. Align the top and bottom edge of the strip, remove the selvages, and place the two strips wrong sides together (WST). Note: When you make a cut, you will be cutting both the right side of the block and the left side.

Place the flat tip of the ruler along the top of the strip, the solid line along the cut side edge, and the 4″ line along the bottom. Cut the angled (right) side.

How to Make a Triangle in a Square Block

Step 4:

Don’t move the fabric strip! Flip the ruler instead, aligning the cut angle with the line that says “Side Triangle Trim #2”.

Slide the ruler so the flat tip is along the bottom. Make a straight cut along the side of the ruler.

You’re back at the beginning again. Continue this process until you have made 16 of the triangles needed for your Midnight Star Table Topper project.

How to Make a Triangle in a Square Block

Step 5:

Separate your left and right side triangles and lay them on either side of your center triangle. Hint: Make sure the two stacks of side triangles are all right side up.

How to Make a Triangle in a Square Block

Matching the cut edges, chain stitch all the left hand triangles to the center triangle.

How to Make a Triangle in a Square Block

Press to the dark side and repeat for the other side. Press the completed block.

How to Make a Triangle in a Square Block

Step 6:

Now it is time to square up your blocks! Place the V Block Ruler on top of your block so the lines of the 4″ V aligns with the seam of the center triangle. Trim along the side and top.

How to Make a Triangle in a Square Block

Now turn the block over and match up the 4-1/2″ line along the side and bottom, with the X along the top. The X should match up with your point. Trim along the side and top.

How to Make a Triangle in a Square Block

Wasn’t that funWhen you have the right tool, it’s easy it is to make Triangles in a Square!

Now, make seven more Triangles in a Square using Dark Blue and White fabric. When you’re done, you will have eight identical Triangle in a Square blocks.

Set these eight Triangle in a Square blocks aside because they are going to be part of the Midnight Star Table Topper which will be in an upcoming post.

How to Make a Triangle in a Square Block

This block is part of a fun project called the Midnight Star Table Topper. This post is Part 1 and below are links to Part 2 and Part 3.

Part 2: How to Make Magic 8 Half Square Triangles 

Part 3: How to Make a Square in a Square Block

Part 4: The Midnight Start Table Topper Pattern 


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10 Comments

  1. This is great! I just made a quilt with triangles, squares, etc. I wish I’d known about this technique.

    Roberta Hartley

  2. Looking forward to the new pattern. One question tho….could you give sizes and measurements to make the blocks for those of us that can’t afford to purchase a new ruler right now?

    1. There will be more details when the pattern is available. But, you can trim to 4-1/2″ square using any ruler. The V Block ruler just makes it absolutely perfect.

    1. Sure, most rulers have 45-degree and 60-degree markings. It might take a little figuring out, but it certainly can be done. You could also cut a cardboard template, draw the lines then cut with rotary cutter and mat.

  3. Found your Midnight Star block on Grace Co newsletter. I just love it and the Studio 180 Tools. I going to try it in Christmas colors.

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