How to draw a triquetra using a right-angle triangle

​A triquetra (or trinity knot as it’s sometimes called) can be a handy design element to put in corners as a stylish way to fill space. In this tutorial, we will draw a triquetra using a right-angle triangle that puts the point of one loop into the 90˚ corner.

No special supplies are needed for this tutorial, just a pencil, eraser, paper, and a straight-edge. But if you are not using grid paper a T-square or L-square might come in handy. If you don’t have grid paper or a T-square use a piece of paper folded into quarters.

Remember to draw your triangle and initial arcs lightly as it is only a guide that will be erased.

So let’s get to it!

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Gather your supplies:

Drawing pencils
Markers
Blending stumps
Eraser
Click eraser
Ruler
Horse hair brush
Grid paper
Sketch pad
T-square or L-square

Step 1:

Draw a triangle creating one 90˚ corner. if you’re a confident drawer you can freehand. Or you can use a straight-edge or L-square to get an accurate angle. Draw your triangle large enough to accommodate overlapping details and negative space between them. The two lines that form the corner can be any length you desire and don’t have to be the same length. Different lengths will produce interesting variations in your triquetra.

Step 2:

Draw a half-circle or arc from one corner, around the triangle’s center point, and end in the opposite corner. (You can guestimate the center of the triangle but if you’d like to know how to find the exact center of a triangle check out my YouTube video or blog tutorial.)

Step 3:

Follow the same steps to create the other two arcs. 

Step 4:

Now that you have the basic single line of the triquetra, draw offset lines to make the line into a thread. These lines will run parallel to the lines drawn and can be above or below the single line. Your thread can be as thick or as thin as you like. The only caution here is to leave enough space in the center for the over and under weave.

Step 5:

Now it’s time for the alternating overs and unders. Pick one point of intersection and decide which thread will go over the other. Erase lines you don’t need. Follow that thread to the next intersection and do the opposite—if you went OVER the first intersection you will go UNDER this intersection. Move on to the third intersection. If you went UNDER the last thread go OVER this one. Follow the thread back to the beginning and check that you have properly woven your thread alternating overs and unders.

Step 6:

Erase all unnecessary guidelines, darken your lines, and stylize!

Here is the YouTube video tutorial for you to watch…
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Related blogs you may want to read:
How to find the center of a triangle
How to draw a Celtic triquetra using an equilateral triangle
How to draw a simple Celtic triquetra using three circles
How to find the midpoint of a line, arc, and circle without measuring
Step-by-step method for drawing a basic triskele
Creating a knotwork pattern inspired by the Clonmacnoise South Cross
Drawing tutorials for Celtic knot borders and corners
Circular Celtic border knot tutorial, basic braid
Basic twist step-by-step drawing tutorial using grid paper
Celtic braid step-by-step drawing tutorial
Basic border knot with vertical breaks, step-by-step drawing tutorial
Basic border knot with horizontal breaks, step-by-step drawing tutorial
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A fun DIY project with paint and a thrifted mirror part 2
The Celtic Motherhood Knot, a symbol of love
Celtic Tree of Life
Basic Celtic Knot Tutorial Part 1
Celtic Knot Tutorial Part 2