I started from oak lumber, which I cut down to size and then planed. I made six 308 mm wide panels.
To create the pentagons with a 190 mm edge length, I used a table saw and made a jig with an offset at 18 degrees.
The blade angle was set it to 31.7 degrees because, according to Wikipedia, the dihedral angle of a dodecahedron is 2arctan(ϕ), where ϕ is the golden ratio.
For assembly, I used flat glue and secured the joints with tape to ensure everything held together while the adhesive cured. This method allowed for a clean finish.
Now, I just hope my cat will use it! 😉
If they cat don’t like it I’ll trade you an Amazon box for it that’s guaranteed! Comes with the cat 😉