# Get equations of segments and arcs in Geogebra 6

Leche Q. shared this question 3 years ago

I have to trace a simple image using equations (line segments, arcs, etc). I tried using Geogebra Classic 6 but the result was a disgrace. I traced everything just to realize there ain't a way to obtain the equations behind line segments nor arcs. It only shows their length (The one equation is from an Ellipse, and is the only shape with it). Please tell me if there's a way to either get them from the ggb file I already have or to start again in other software that works just like Geogebra, where you can place the dots and easily trace the arcs and segments, allowing a background image to be used

1

Sorry no: segments and arcs are geometric objects, so the displayed values refer to their length.

The equations of the generating objects are displayed only if you create the whole object, e.g. the ellipse whose arc is tracing your image.

1

Hello Leche!

As Simona said - not directly ... but ...

Hmm, if you want the equation of your circles, than you have to calculate or "construct" the equation of a circumscribed circle: https://en.wikipedia.org/wiki/Circumscribed_circle

You can build a custom tool with three points input and it will give you the needed equation.

If help is needed I am pretty sure, that many people can help you or look here for circumscribed circle or circumcircle: https://www.geogebra.org/search

So it is not so much to do to save your work. You have already selected the points and determined the circumcular arcs, probably get with the given tool of GeoGebra, and now you use the same points with another tool to get the equation of the complete circle.

Kind Regards and I hope it helps you

mire2

PS: Ok, build a tool (you can see at the ending, it is .ggt not .ggb) you can open and use it - not very nice, but I hope it works in GeoGebra 6.

You have to open it with GeoGebra and should find a new icon in your task bar.

The command is "circumcircle" and you use it by clicking on your selected points or by input:

`circumcircle(<point>, <point>, <point>)`

2

LOOOL - I am such a unbelievable clever and smart guy. :-D

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