Drawing an Arc Length

[Anonymous]

Is there any way to draw a precise Arc length using Archicad?

I am working from a surveyor's drawing, and need to input the arc length with a given radius.

(I think I know the answer is "no" or "buy an add-on" but I am posing the question so I can ask the next question: Why not? )

[Anonymous]

Not to my knowledge, the only way I have found is to dimension the arc and adjust it as you can to get the length. If anyone else has a trick, I'd also be happy to hear it.

As for the second question : I have no idea.

[Erika Epstein]

Other than calculating it geometrically,

You could try opening the
Element Information window/palette under
Windows,
Floating Palettes.
Draw the arc with the given radius. In the Element Information window chose the "last Selection" radio button. This will give you the length of the arc you drew and then you can 'stretch' the arch like stretching a wall (cmd/ctrl H) and then type in the difference to stretch the arc to the specific length you want.

Note it doesn't give you the radius, just the angle but if you know the radius you have enough information to accomplish what you want.

[Jacek]

Erika wrote:
Other than calculating it geometrically,

You could try opening the
Element Information window/palette under
Windows,
Floating Palettes.
Draw the arc with the given radius. In the Element Information

Erika, great Tip!
I have almost forgatten about this feature! Used it a while ago and since forgot about this 'little gem' - Thank you.

[Anonymous]

Hey Erika,

I really like the info palette, but i still don't get to PRECISELY input an arc length. If the info palette was interactive, now how cool would that be?

Or am I not understanding how to use it properly?

[Erika Epstein]

To input the distance once you have done cmd/ctr H type in "r" and the the distance. In this instance 'r' refers to the length you are adding/subtracting to the arc, NOT the radius.

Yes, it would be nice if it were interactive. As I am a stickler for precision, I would still be entering the exact dimension, not eyeballing it.

[Seiss Wagner]

Finding the length of an arc (circumference) is of interest, but of limited value. A much more interesting and useful question is how do you draw an arc knowning the cord length and radius without resorting to geometry?

[Jacek]

Seiss wrote:
,,,, A much more interesting and useful question is how do you draw an arc knowning the cord length and radius without resorting to geometry?

Hmmm... would you not be able to generate an arc by using the third elipse tool; establish your radious (r=?), then input your cord length (x=?), and complete your arc?

[Jacek]

Seiss wrote:
,,,, A much more interesting and useful question is how do you draw an arc knowning the cord length and radius without resorting to geometry?

Hmmm... would you not be able to generate an arc by using the third elipse tool; establish your radious (r=?), then input your cord length (x=?), and complete your arc?

By the way, where are you going?

[Seiss Wagner]

By the way, where are you going?

Jacek - I am going dyslexic by way of the way of the "radious".

I don't think the third elipse tool would work. I have tried various strategies with the three point circle tool, with no success.