That sounds great! What thickness is the pvc pipe, what is that cutting tool called that you used, and are the pipes all exactly 20cm shorter than each other ascending?
"...what is that cutting tool called that you used" -it is called a "PVC Pipe Cutter," -sold wherever PVC pipe and accessories for PVC (PVC glue, etc.) are sold. You can also use a copper tubing cutter. These are small hand-held 'C-clamp' devices that you rotate around the pipe, scoring it deeper and deeper until it separates. I prefer the copper pipe cutter as it neatly bevels the outer edge of the pipe whereas the PVC Pipe Cutter leave an acute edge that needs to be lightly sanded...
The pipe looks to be 1/2 inch schedule 40. The tool is just called a PVC cutter. And his longest tube was 20 cm, so they aren't 20 cm shorter than each other. I'm not that good with the metric system, but I'd say they're 5 cm shorter than each other, making them 20 cm, 15 cm, and 10 cm
