Eilat Aquarium

How to cut the profile on 2 internal angles.I 90 degrees cuttong believe a CNC machine is needed, but the quote I received from the company in my city, Eilat. is very expensive.As is a glass tunnel aquarium prototype, I want to keep costs down until the test is completed.I prepared a simple outline of what is required, but can not "paste" it here.How do I display the picture?

First What is the thickness of the glass you need? Is it square cuts? Perhaps connecting two tanks together?