How to Send Exact Measurements for Irregular Shapes Without Iterative Fitting

The frustrating back-and-forth of ordering custom parts that don't quite fit. A real case of replacing a broken glass panel in an old window frame.

Key points:
Four side lengths do not fully define an irregular four-sided shape; angles or diagonals matter.
A scaled drawing with segment labels is less ambiguous than a text message, photo, or handwritten sketch.
PDF export is easy to read; DXF export can be used by CAD or cutting workflows when needed.
A few minutes spent on a measured drawing can avoid remakes, extra shop trips, and material waste.