# How to visualy show the length of a segment?

sanjyutu shared this question 2 years ago

How can we show the length of a segment in a visual way so that it is not misunderstood as a name or size of area?

I want to show it in a way like this.

Best regards,

Instead of UserTool you can use the possibilities of Table.

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You could make a custom tool to do that

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https://www.geogebra.org/ma...

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Thank you. I understood how to draw double headed arrow.

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@ mike

I thought the same.. But it's a must to have (minimally) the length of Text/Caption or (better) the center of the rotated Text/Caption. But the command Corner(<text>, <number>) works not in UserTools.

See attached (not working) UserTool (GGB 5).

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Thank you. It took some time to understand the detail, but I now understand how it works.

It satisfies most of my requirement. But position of the caption is not ideal when we move or rotate the segment.

Based on your idea, I found out that we can get a better result by

1. Add rotateTextHidden = RotateText[caption, Mod[Angle[Direction[segment]] + π/2, π] - π/2]
2. Add rotateText = RotateText[caption, Mod[Angle[Direction[segment]] + π/2, π] - π/2]
3. Set the [Starting Point] of rotateText to Midpoint[Point[segment, 0] , Point[segment, 1]] + UnitPerpendicularVector[Direction[segment]] + (Corner[rotateTextHidden, 4] - Corner[rotateTextHidden, 2]) / 2

But the problem is that I can't create a custom tool which set the [Starting Point] of rotateText based on rotateTextHidden. Probably I need to create manually when I want fine control.

I will try to understand another file you made for me.

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espero que se entienda en español

la herramienta de Rami funciona bien; solo tiene un problema de actualización. Haz lo siguiente: crea un segmento, un punto y un texto, pero no ocultes el texto. entonces usa la herramienta haciendo clic sobre el segmento el punto y el texto. se creará una doble flecha y un texto indefinido. a continuación mueve el texto que has usado.

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ooohhh! pero depués no se mueve dinamicamente!! lastima

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Instead of UserTool you can use the possibilities of Table.

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Thanks!

I didn't know that the spreadsheet can be used to manage objects. I was having problem when creating many objects. Happy to know the technique.

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I created four "Angle & distance markers" tools.

They are very old. I don't know if they exist on the new GGB activities website yet. (I uploaded them to the old site many years ago.)

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Thank you for showing another technique to draw double headed arrow. Great technique to draw circular arrow.

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Thank you for the files.

I hope that some of the tools to be included as a standard tool of GeoGebra.