Within the Tetrahelix there is also an Octahelix, a Cuboctahelix and an Icosahelix.
Here is an interactive web page that lets you explore and see how these different helix fit inside the Tetrahelix.
The controls to the interactive web page assumes a 3-button mouse.
The left button will rotate the scene displayed (the Tetrahelix).
The center button or wheel will zoom the scene in and out.
The right mouse button will drag the scene with the mouse.
I am not familar with Apple computer, so I do not know what the equivalent mouse functions will be.
Here is the Tetrahelix.
And the Octahelix within the Tetrahelix.
And the Icosahelix within the Tetrahelix.
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