Radius of an arc

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Mikerosen
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Joined: Sun Dec 11, 2011 6:16 pm
Location: Seattle, WA, USA
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Radius of an arc

Post by Mikerosen »

Eric,
I'm sure I've asked this before. How do I determine the radius of a 3-point arc?
Thanks,
Mike
Mike Rosen
Seattle, WA, USA

Mac OS Ventura 13.1, iOS 11.4.1 on iPad Pro
Eric Pousse
Posts: 1064
Joined: Sat Dec 03, 2011 12:31 pm
Location: Tours - France

Re: Radius of an arc

Post by Eric Pousse »

Bonjour Mike,

You don't have to determine it, RealCADD do it for you.

Cordialement.
Eric Pousse
Mikerosen
Posts: 339
Joined: Sun Dec 11, 2011 6:16 pm
Location: Seattle, WA, USA
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Re: Radius of an arc

Post by Mikerosen »

Sorry! I should have said, "how do I use the dimension tool to show me the radius of an arc?"

And on top of that, I just realized this is the wrong forum!

How do I use the dimension tool to show me the radius of an arc in iPocket Draw?

Sorry...
Mike Rosen
Seattle, WA, USA

Mac OS Ventura 13.1, iOS 11.4.1 on iPad Pro
debenriver
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Location: Maine USA and Suffolk England
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Re: Radius of an arc

Post by debenriver »

Hi Mike

The simple answer is you can't – there isn't a radius dimension tool or a diameter dimension tool.

The standard length dimension tool will measure a diameter – but won't give you a diameter symbol (ø or Ø, d or D).

My Auto-size line script will do it – in metric or decimal US units (won't cope with fractional feet or fractional inches). And you can put in whatever leading or trailing symbols/text you want. It's not perfect but I use it all the time. Someday I'll perfect it (or ask Eric to!).

Ref your original question as asked :D – as far as I remember from schoolboy geometry there is only one circle whose circumference will pass through three non co-linear points and once you've drawn it, RealCADD does indeed tell you what the radius is. I often use this tool actually. If the three points are co-linear, then you have a straight line – which you could consider to be a circle of infinite radius ... if you really want to be pedantic about it :ugeek:

Have you tried the beta10? I'm having just a tiddly bit of trouble getting to grips with it. And I don't think it will draw a circle through three points!

Cheers -- George
debenriver
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Location: Maine USA and Suffolk England
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Re: Radius of an arc

Post by debenriver »

Oh – now I've read it more – I see it's iPocketdraw not RealCADD – don't know if the answer I gave is good for that!

One of these days I'll get me an iPad ...

George

:D
Eric Pousse
Posts: 1064
Joined: Sat Dec 03, 2011 12:31 pm
Location: Tours - France

Re: Radius of an arc

Post by Eric Pousse »

Bonjour Mike,

With RealCADD like with iPocket Draw, there is no tool to do that directly.
You have to do it manually.

Cordialement.
Eric Pousse
Mikerosen
Posts: 339
Joined: Sun Dec 11, 2011 6:16 pm
Location: Seattle, WA, USA
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Re: Radius of an arc

Post by Mikerosen »

I'm moving this discussion to the iPocket Draw forum.
Mike Rosen
Seattle, WA, USA

Mac OS Ventura 13.1, iOS 11.4.1 on iPad Pro
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