How to compare mouse position in widget to the area of an image located in the widget?

I’m trying to make a drawing game where you trace out a shape and get scored based on your accuracy to the shape.

I figured that I could get the accuracy by placing points along the shape so that when the player draws over these points.

The issue is I can’t figure out how to make this happen in widgets. I thought I could just put a button, but the drawing doesn’t overlap over the button, so it just breaks the line that’s being drawn.

Basically, how can I make it so that when the mouse enters an specific area on the widget, something happens