I am looking for an open source program where I can draw lines, designate parallel constraints, define distances, etc. and then at the end, I can ask "what is this area [between 4 points] in terms of these distances?", and it will give me a formula something like D1 * (D2 + D3) - D4 * D5. I would very much prefer to be able to see the constructions graphically. If I can also edit the constructions graphically (point and click) rather than learn some kind of geometry programming language, that would be ideal but not essential.

I tried using GeoGebra but couldn't find a way for it to tell me a formula.

I am using Ubuntu operating system.

1 Answer 1


I think the best software for your needs is indeed Geogebra, I personally prefer the classic web version. Geogebra is like... the most user-friendly graphing calculator that I can found; other graphing calculator software can be equal or even more complex than Geogebra.

If you want to get the most of it, eventually you will need to learn how to use it like a pro, and that can apply to every graphing calculator software.

The best method, is playing with it.

A little tutorial: distance between points

In Geogebra, you can use the name of the objects you create as variables to other equations. In your example, this can be achieved like this:

  • You create points in the plane.


  • Use the "Distance or Length" tool, and select two points. You can do it many times for every pair of points if you want.


  • Here, I selected point A-B, and B-C. That will create some objects. The objects distanceAB and distanceBC are the interesting ones, they hold values (notice the number below them).

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  • Use those names in a equation to use them as variables.

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Furthermore, if you move your points with the mouse, the equation will change in real-time.

If you want to change the name of those objects, you can right-click them and select "Rename".

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The name will be updated across all equations.

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