DIY Pentakis Dodecahedron With Your Kids

We had no idea what we were making at first.  We were noodling around with a pack of straws, and we discovered that it was that it was possible to make colorful triangles.  The sides of these triangles were all the same length.  We learned that triangles whose sides are all the same length are called equilateral triangles.

To make an equilateral triangle from flexible straws, join them together short end to long end, using the flexible parts as the corners.  The corner of a triangle is called a vertex.

The best way we could find for joining the straws together was to squish one end flat against a hard surface using our thumbs.  Then put a crease down the center of the flat end using a butter knife.  Pinching the crease together, slide the small end into the long end of another straw, like an arm going into a sleeve.

Step 1 Start Joining Together Triangles to See What Happens

We decided to try using our hot glue gun to stick triangles together with their vertices all sharing a single point.   As we added triangles, eventually we were able to make a kind of 5-faced squat pyramid shape.   We thought it was pretty.

We discovered that the straws stayed together if you put the hot glue blobs on the joints, where the straws come together.  The hot glue slightly melted through the outside of the place where the straws came together, making them hold.

At this stage, we had to blow on the glue to get it to set while holding the straws together firmly.  Later on, we discovered a better way.