Radius of an arc

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Mikerosen
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Radius of an arc

Post by Mikerosen » Tue Jul 14, 2015 9:27 pm

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 10.13.6, iOS 11.4.1 on iPad Pro

Eric Pousse
Posts: 655
Joined: Sat Dec 03, 2011 12:31 pm
Location: Tours - France

Re: Radius of an arc

Post by Eric Pousse » Wed Jul 15, 2015 8:28 am

Bonjour Mike,

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

Cordialement.
Eric Pousse

Mikerosen
Posts: 272
Joined: Sun Dec 11, 2011 6:16 pm
Location: Seattle, WA, USA
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Re: Radius of an arc

Post by Mikerosen » Wed Jul 15, 2015 9:13 pm

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 10.13.6, 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 » Wed Jul 15, 2015 11:33 pm

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 » Wed Jul 15, 2015 11:47 pm

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: 655
Joined: Sat Dec 03, 2011 12:31 pm
Location: Tours - France

Re: Radius of an arc

Post by Eric Pousse » Thu Jul 16, 2015 7:48 am

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: 272
Joined: Sun Dec 11, 2011 6:16 pm
Location: Seattle, WA, USA
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Re: Radius of an arc

Post by Mikerosen » Thu Jul 16, 2015 1:37 pm

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

Mac OS 10.13.6, iOS 11.4.1 on iPad Pro

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