Some stages of making the template.

With ruler

With light

Folded

On canvas

With line

With nail

With cut

Geometrico modello finestra.

Here's an image of the geometric plan for my Windows installation.

I made a few incisions to the paper, both to align the grid on canvas and to document the curves.

Some noted geometric observations.

1000mm

70mm

100mm

35mm

10mm

130mm

500mm

50mm

Windows diagram.

The diagram.

Ideas, doodles and thoughts.