# Concave or Not

acron shared this question 2 years ago

This is an attempt to use an If-statement to determine whether a figure is concave or not (convex).

I can place E and F inside or on a quadrilateral. I do not want it on a side, however.

I would like to write an if where If (j is inside q1, "Convex","Concave")

Possibly, no such command is available.

https://www.geogebra.org/m/hbuwhefa

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I assume you're looking for something is similar to the attachment (see the red commands). The principle is to check all angles.

It is possible to create a User-Tool (Input: <polygon> / output: Text (at the Centroid) and/or Boolean )

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I think it's possible to expand this method to any polygon.

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for any polygon

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Rami’s file solves your question 🙂 I just wanted to mention IsinRegion command, that might be useful. https://wiki.geogebra.org/e...

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And two possibilities more

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test this method

Files: foro.ggb
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I found one solution more.

But no feedback from your side until now so I think your question is obsolete and I delete this thread from my watching list.

Quote: "Possibly, no such command is available.". Answer No: you can use IntersectPath()