I'm fairly new to Geometry Nodes.
I'm trying to create a certain amount of $90°$ arcs using Geometry Nodes, where each arc has a different radius but a common center point, such that the distance between each arc is constant.

I also want the arcs to only start after a certain threshold value (t in this example)

My current setup is as follows:

That yields the following result:

Currently the center of each arc moves along the initially generated line. Instead of that, I want to keep the center the same but change the radius instead. How can I achieve this?