Instance on Points with different parameters for each instance

Question

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?

Answer 1

Since an arc by default is drawn with the compass needle in the origin, once it becomes an instance, scaling the instance will look like simply modifying the radius - without displacing the arc. So if you create an arc with $r=1$, the (uniform) scale of the instance will equal its radius:

Answer 2

I would solve this task as follows:

Here, I first convert the arc into an instance, so that I can easily scale it to a specific value at the end.

I achieve the duplication not by instantiating on a Mesh Line but directly with the node Duplicate Elements.

With the index of the duplicate I can then on the one hand remove the instances at the beginning, and on the other hand do the scaling.

_{(Blender 3.6+)}