This is damned cool. Having something like this makes it easy and convenient to explore geometry without the inconveniences imposed by physical media. Having specific goals to work towards and target move counts is icing on the cake.

Thank you for making this. Find a way to get this out there to geometry teachers. They (and their students) will love it.

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Suggested improvements:

+ Option to switch between a couple colors or line types, to make it easier to track what one's doing. (E.g., laying down foundational lines in black, then experimental lines in blue or dashed lines.

+ One minor thing I'd like to see fixed: the proximity of the numerical goals to the shapes they're associated with doesn't make it clear whether (e.g.) the 8 move goal is an easy version of the "build a triangle in X moves," or whether 8 moves is the least amount of moves for building a triangle inside an origin circle.

Suggested fix: make that more apparent by tweaking the order of the symbols (e.g. Triangle, 5, 8, OriginTriangle) and/or adding a divider of some manner to make them stand apart more.