CAD a D12

The goal of this instructable is to CAD a D12 (dodecahedron) with only 1 parameter

Supplies

CAD Software, I use OnShape as it is free

Make an inscribed pentagon on the "Top" plane
Make a point of the pentagon be connected to the "Right" plane
Add your one dimension to say how big the circle is
Add a construction line from the constrained point down along the "Right" plane
Make the construction line be equal (same length as) the side of the pentagon
Add a construction line from the bottom of the pentagon to the outside of the construction circle

Make a construction line the height of the pentagon
Make a construction circle from the base of the pentagon to the top of the pentagon
Make a construction circle from the top of the pentagon to end of the construction line representing the length of a side
Make a rough hexagon
Start from the outside of the large construction circle
Go to the construction line used for the height of the triangle
Then go to the edge of the small construction circle
Constrain the hexagon's length
4 off the sides are the same length as the height of the hexagon
The other two are the length of the side of the hexagon
Make opposite sides of the hexagon the same length
Long > Long > Short > Long > Long > Short
Make opposite sides of the hexagon parallel to each other
Add construction across the hexagon using the short lines to make a rectangle
Constrain the crossing lines to be perpendicular to the short lines
Add a construction line through across the hexagon, connecting the points where to long lines meet
Add a point at the midpoint of this line
This will be the center of the object
Constrain the midpoint to be in plane with the center point of the pentagon

Rotate the object 3x evenly around various edges until there is a full D12 shape

You now have a "blank" D12!

Feel free to add numbers to it or whatever else you want!