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Easy Triangle Quilting Patterns

Updated on February 28, 2017
calculus-geometry profile image

TR Smith is a product designer and former teacher who uses math in her work every day.

You can create an endless number of unique quilt designs using half-square triangles. Half-square triangles, also known as isosceles right triangles, tessellate perfectly and can be arranged to create stars, flowers, pinwheels, stripes, diamonds, diagonals, animal shapes, and much more. It's possible to sew a quilt using nothing but equal sized half-square triangles, which means you can cut your triangular patches in bulk to save time.

Below are galleries of patterns using half-square triangles to give you some idea of the types of quilt designs that are possible. From the basic quilting blocks you can devise even more intricate patterns. The best way to create your own quilt patterns is to print sheets of blank square grid paper, divide the boxes into triangles according to design you have in mind, then shade the triangles with colored pencils or markers.


Basic Principles

In a half-square triangle quilt pattern, every triangle is matched with another to form a square block. There are two ways that two square blocks can be placed adjacent to each other, labeled as Arrangements A and B in the diagram on the right.

Most quilt patterns use a mixture of these two arrangements, which gives rise to the practically infinite number of different triangular designs you can quilt. However, there is one pattern that exclusively uses Arrangement A, and one pattern that exclusively uses Arrangement B, shown in the diagrams below.

One of the best tools for quilters who need to cut triangles.
One of the best tools for quilters who need to cut triangles.

Easy Cutting Tool For Triangular Quilt Patches

A rotary cutting tool like a pizza cutter is the best way to cut hundreds of identical shapes precisely so that the edges match up perfectly. For example, the Fiskars rotary cutting set lets you cut multiple layers of fabric at once without the fabric slipping, so you'll always end up with a perfect stack of identical patches to make your picture-perfect quilt. The board has grid lines and a 45° angle line to help you cut half-square triangles accurately.

If you prefer to use scissors, it is wise to invest in a blade sharpener and never use your fabric scissors to cut anything but fabric. Paper products contain traces of hard minerals that act as abrasives on the metal blades.

Some Galleries of Half-Square Triangle Quilt Patterns

Here are diagrams of triangular arrangements used to create various motifs and traditional quilting patterns. Some quilting pattern blocks have traditional names, often more than one. For a list of names, see this resource or this resource.

A fun way to create your own quilting blocks besides drawing them on grid paper is to use tangrams. Solving tangram puzzles uses the same part of your brain as quilting, and can inspire you to devise new blocks and patterns you never thought possible with mere triangles and squares.

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Basic grid Basic diagonal gridPinwheel quilting blocksCross quilting blocksPinwheels and arrow quilting blocksSpiral and pinwheel quilting blocksDevil's puzzle, spiral and flower quilting blocksDutchman's puzzle and variation quilt blocksStar and zigzag quilt blocksArrow quilt blocksStar and spiral quilt blocksArrow and pinwheel quilt blocksStripe and pinwheel quilt blocksSquare pattern quilt blocksFish and pinwheel quilt blocks.Jacob's ladder, flower and pinwheel quilt blocksPinwheel and flower quilt blocksTerrier, butterfly, flower, stretching cat, insect and fish quilt blocks.Flowers, birds, jellyfish, pinwheel, and zigzag quilt blocks.
Basic grid
Basic grid
Basic diagonal grid
Basic diagonal grid
Pinwheel quilting blocks
Pinwheel quilting blocks
Cross quilting blocks
Cross quilting blocks
Pinwheels and arrow quilting blocks
Pinwheels and arrow quilting blocks
Spiral and pinwheel quilting blocks
Spiral and pinwheel quilting blocks
Devil's puzzle, spiral and flower quilting blocks
Devil's puzzle, spiral and flower quilting blocks
Dutchman's puzzle and variation quilt blocks
Dutchman's puzzle and variation quilt blocks
Star and zigzag quilt blocks
Star and zigzag quilt blocks
Arrow quilt blocks
Arrow quilt blocks
Star and spiral quilt blocks
Star and spiral quilt blocks
Arrow and pinwheel quilt blocks
Arrow and pinwheel quilt blocks
Stripe and pinwheel quilt blocks
Stripe and pinwheel quilt blocks
Square pattern quilt blocks
Square pattern quilt blocks
Fish and pinwheel quilt blocks.
Fish and pinwheel quilt blocks.
Jacob's ladder, flower and pinwheel quilt blocks
Jacob's ladder, flower and pinwheel quilt blocks
Pinwheel and flower quilt blocks
Pinwheel and flower quilt blocks
Terrier, butterfly, flower, stretching cat, insect and fish quilt blocks.
Terrier, butterfly, flower, stretching cat, insect and fish quilt blocks.
Flowers, birds, jellyfish, pinwheel, and zigzag quilt blocks.
Flowers, birds, jellyfish, pinwheel, and zigzag quilt blocks.

Some Tessellating Quilt Block Patterns

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Tessellating maple leaf quilting pattern.Tessellating flower quilt block pattern.Tessellating school of fish quilt pattern.Tessellating arrows quilting pattern.Basic tessellating cat quilt pattern.Fancy tessellating cat quilt pattern, tails curled.Fancy tessellating cat quilt pattern, tails up.Tessellating cat face quilt pattern.Tessellating Christmas tree or fir tree quilt pattern.Tessellating squirrel quilt pattern.
Tessellating maple leaf quilting pattern.
Tessellating maple leaf quilting pattern.
Tessellating flower quilt block pattern.
Tessellating flower quilt block pattern.
Tessellating school of fish quilt pattern.
Tessellating school of fish quilt pattern.
Tessellating arrows quilting pattern.
Tessellating arrows quilting pattern.
Basic tessellating cat quilt pattern.
Basic tessellating cat quilt pattern.
Fancy tessellating cat quilt pattern, tails curled.
Fancy tessellating cat quilt pattern, tails curled.
Fancy tessellating cat quilt pattern, tails up.
Fancy tessellating cat quilt pattern, tails up.
Tessellating cat face quilt pattern.
Tessellating cat face quilt pattern.
Tessellating Christmas tree or fir tree quilt pattern.
Tessellating Christmas tree or fir tree quilt pattern.
Tessellating squirrel quilt pattern.
Tessellating squirrel quilt pattern.

Above are ten tessellating quilt patterns that require only squares and half-square triangles. Tessellating cats make a quirky and fun patchwork project, ideal for children's bedding or unique hand-made gifts. Tessellating cats and tessellating squirrels can be embellished with buttons and embroidery to bring out the details of the face and body. For fun, you can combine the tessellating cats, fish, and squirrels in the same blanket. The tiling flower pattern is ideal for adult bedding or sofa covers.

8-Pointed Stars and Octagons

With squares and half-square triangles you can create 8-pointed star and flower patterns and octagonal motifs. When designing star quilt blocks, it's important to know that the ratio of a square's diagonal to its side is sqrt(2):1, or approximately 1.414 to 1.

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Some Quilting Math

When piecing together triangles to make an 8-pointed star block, you should pick lengths so that the straight vertical and horizontal lengths are approximately equal to the diagonal lengths. This can be achieved using the 3&2, 4&3, and 7&5 ratios shown in the diagram below. When the straight sides have lengths 3, 4 and 7, the diagonal lengths are approximately 2.828, 4.243, and 7.071, which allows you to make stars with almost perfect 8-way symmetry.

The reason why these length pairs produce an aesthetically pleasing effect for eight-pointed stars is because 3/2, 4/3, and 7/5 are increasing better and better approximations of the square root of 2. The square root of 2 is approximately 1.4142 and it is important in quilting math because it is the length of the diagonal of a square whose sides have length equal to 1. You can use this square root of 2 aspect ratio calculator to find larger number pairs (such as 11&8, 17&12, or 23&16) that give a ratio close to the square root of 2.


Number of Triangles Needed

If the quilted area inside the border is L inches long by W inches wide, and you are only using half-square triangles that are T inches long on the sides (not diagonal), then the number of triangles you need is given by the formula

Number = (2*W*L) / T^2

For example, if the quilted area is to be 80 inches long by 60 inches wide, and the triangles are 5 inches along the sides, then you compute

Number = (2*60*80) / 25
= 9600/25
= 384

so you need to cut 384 triangles to complete the quilt.

Seam Allowance for Isosceles Right Triangle Quilt Patches

For isosceles right triangle patches, if you want to have a 1/4-inch seam allowance then you need to cut the triangles so they are larger than the finished triangle by 7/8 inches. For example, if the size of the half-square triangles is 4 inches (measured along the short sides) when they are sewn into the quilt, then the size of the raw fabric pieces must be 4 7/8 inches.

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    • prestonandkate profile image

      Preston and Kate 3 years ago from the Midwest

      This is fascinating to me! Do you create all the grids / patterns yourself? I could have NEVER come up with all those patterns created from half square triangles. I am amazed! Great and informative hub! -Kate

    • calculus-geometry profile image
      Author

      TR Smith 3 years ago from Eastern Europe

      Thank you for the kind comment. Some of them are my own creation, some are from patterns I've seen on other quilts and in books. Sometimes I see interesting quilt blocks without the grid lines and have to figure out the square and triangle divisions myself, so there must be many variations on these patterns. I did make all the grids myself in MS Paint, but I usually use graph paper or play around with tangram shapes.

    • Suzanne Day profile image

      Suzanne Day 3 years ago from Melbourne, Victoria, Australia

      A lovely hub, packed with useful information for any quilter! Now...if only I hadn't used up half my fabrics making rag rugs, I would be able to try one of these - especially with the beautiful colourwash gradation as shown in the top pic. I've made one quilt before. It took 2 years by hand for a double bedspread, but I've collected that many books, pics and patterns "just in case" I suddenly get the urge to get right into it. Voted useful ;)

    • calculus-geometry profile image
      Author

      TR Smith 3 years ago from Eastern Europe

      Thank you. I'm a quilt pattern hoarder myself.

    • moonlake profile image

      moonlake 3 years ago from America

      Very nice hub voted up. I like doing the triangle quilting patterns. These are fun to do with left over fabric. I have plenty of fabric I need to use up. No time now for it.

    • Barbara Kay profile image

      Barbara Kay Badder 3 years ago from USA

      Nice quilting patterns! I use to sew these, but finally stopped. I ran out of people to give them to!

    • bettyshares profile image

      bettyshares 2 years ago from Lighthearted Musings

      I like these quilting patterns it reminds me of my childhood where my grandmother used to sew blankets.

    • profile image

      Terry 2 years ago

      This info would be great app.

    • SEXYLADYDEE profile image

      SEXYLADYDEE 2 years ago from Upstate NY

      Love this HUB! I am an avid quilter and that flower is on my quilting bucket list. I just completed a wall hanging top using HST in a chevron pattern. Thanks for adding to my skill set. Hope to read more of your work. Voted up. Check out my quilting HUB. Dee

    • profile image

      Janey 21 months ago

      I love the one with just the cat faces. I have lots of cat patterns, but I've never seen this one.

    • profile image

      Fabric Lover 17 months ago

      Well, this site will definitely help bust my stash! Very well done!

    • profile image

      candy norris 15 months ago

      i would like to use your material for a fabric lover's club i host monthly of course giving you full credit. i am currently struggling with typing as i dislocated my left shoulder and broke my right wrist in a fall. i am now just getting to 70% range of motion with my left arm. i have surgery on my right arm Monday. very difficult to type with left hand when right handed. also range of motion makes it difficult to capitalize things. please let me know if i may have your permission and how you would like for me to give you credit.

    • calculus-geometry profile image
      Author

      TR Smith 14 months ago from Eastern Europe

      Hello Candy, thanks for the compliment.

      It is fine to print out the text and images of this webpage and share copies with a small group of friends, or email people a link so that they may visit the webpage themselves. If you do that, then my author name and web address will be visible.

      But please do not transcribe this page or copy its contents onto any digital or print media (e.g., blogs, newsletters, e-books) since the copyright is mine.

      Thank you and best of luck with the surgery and have a happy new year.

    • profile image

      Elaine Stephens 11 months ago

      I would like to see the cat patterns, in marked triangles ... Do you have a diagram for sale, or a book of cat patterns that I could buy?

    • profile image

      Nadine Medlin 10 months ago

      I'm with Elaine. I would like to see the cat pattern in marked triangles. It reminds me of my "Baby" who passed away several months ago. Is there a book or that pattern for sale?

    • profile image

      Susan 7 months ago

      "Sew" informative. I am a retired math teacher so I love your use of tangrams, tessellating patterns, and the math involved in figuring lengths of sides, etc. I need to do a tessellating quilt.

    • profile image

      June 5 months ago

      How do I print out the pattern ??Lovr your designs.

    • profile image

      Judy Adams 4 months ago

      Is there an easy way to download these patterns, are do we just copy the image and save it on a Word page?

    • profile image

      Nina LaFosse 4 months ago

      How do you print out the pattern?

    • calculus-geometry profile image
      Author

      TR Smith 4 months ago from Eastern Europe

      There's no way to download the pictures except to save the whole webpage. You can copy and paste a pattern in a Word document and print it.

    • profile image

      Judy Adams 4 months ago

      Thanks!

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