I was once asked to make an instrument for a Christmas Lighting company. They place Christmas lights along the roof of the house. And they need to have a way to quickly calculate the amount of materials they need (garland length).

It would be convenient to do this from a photograph at home. If you insert a photo in Visio and draw the necessary garlands in it in the form of a polyline on it, then Visio can calculate the length using the LengthIU function. But for success, you need to correctly set the scale of the document and the size of the photo. And this operation seemed unnecessarily complicated for the low-skilled personnel of the company.