I wonder if you can help.
I'm having a bit of a debate with some tiler friends of mine.
The debate is to do with adhesive bed depths.
If I use a trowel withe a square notch, and a depth of 20mm, like this.

I spread my adhesive with the trowel at a 45* angle.

Like so.
What will be the thickness of the adhesive bed?
If you could give me an answer, and some workings out, that would be great.
I wish I'd payed more attention at school.