Transparent shapes in Google Drive

I use Google Drive for my documents, and I wanted to find a way to illustrate the overlapping nature of a Venn diagram. Specifically as it applies to greatest common factor and lowest common multiple. Having an empty shape would work, but using a coloured fill with a lower opacity helps illustrate that the items in the middle belong to both sets.

Happily, Google drive lets us do that. Here's a short video tutorial on how to set that up in a drawing. If you're in a Google doc, you can choose the Insert-Drawing option to put an editable drawing directly into your document.