# Force angle to be between 0 and 90 degress

tush shared this question 6 months ago

Hello

I want to show an angle in my GeoGebra presentation, that lies between the two sides of two line, with the angle between them to have the size of any number from 0° to 90°.

Specifically, I want to visualize the angle between a curve and its perpendicular, and a line through the above intersection.

GeoGebra keeps displaying the obtuse angle.

Actually, if I define a new "point on object" on the two above mentioned lines. I can draw a different angle that span as I want it to. It just that this way I define too many objects on the algebra panel, and it makes the whole project cluttered and over-defined.

An image:

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Please post your .ggb file - it's probably quite easy using If() or Condition to Show Object

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I would like to see an

`If`
condition. I uploaded a slightly different file than the above picture, just to make things cleaner, but the concept of the question is the same.

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try attached

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try attached

Files: foro.ggb
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@ mathmagic

I am looking for a way to define just this acute angle in your file (and in alfabeta2's) file, but without the use of the points `E` and `F` you defined in your file. Is that possible?

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I do not understand why it is better without points

I see you use point(c,0.9) so I think if you do not want F' then you can use point(h,0.6) and point(L_1,0.5) in your file

ie angle(point(h,0.6),point(c,0.9),point(L_1,0.5)

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I do not understand why it is better without points

I see you use point(c,0.9) so I think if you do not want F' then you can use point(h,0.6) and point(L_1,0.5) in your file

ie angle(point(h,0.6),point(c,0.9),point(L_1,0.5)