What do you call a 3D shape that has twenty sides? If you said an icosahedron, you’re right! From my geeky history, a D20 dice comes to mind more than the technical term.

To make this ornament out of paper, you can follow the related tutorial for a 3D Christmas ornament.   The concept is the same: take 20 circles and fold the edges to form equilateral triangles, attaching them edge to edge in order to build the twenty sided shape.

The difference between these two processes is that instead of attaching them together with the edges towards the outside, the edges are folded into the inside.

First, make sure you read the original tutorial. Go on. I’ll wait.

You read it? Good!

When you get to step 2, instead of placing the triangle template on a face-up circle, have the pattern facing down and the white backing facing up.  Fold the protruding curved edges over the edge of the triangle template.  Repeat until all 20 circles are folded.

Follow the tutorial, assembling the shapes with the folded edges facing inward.  It’s more difficult to press the sides together, but do your best.  Assemble the five units on the base, and 10 units around the base.

Assemble one set of five units separately from the rest.  This set acts as a hat: add double sided tape to the edges of the base (add a ribbon to hang if you like), then press the hat against the base.  Push, push, push, and hope your tape is tacky enough to hold the pieces together.  You’ll end up with something like below:

Comparing the results of the the two techniques, I prefer the previous tutorial’s edges for adding texture and fun to the tree.  Which do you prefer?