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CircularSegment[] command

acron shared this idea 10 years ago

Answered

There exists

Segment[ <Point A>, <Point B> ]

... Creates a segment between two points A and B.

Segment[ <Point A>, <Number a> ]

... Creates a segment with length a and starting point A.

And there is

CircumcircularSector[Point A, Point B, Point C]

... Creates a circular sector whose arc runs through the three points A, B, and C. Point A is the starting point and point C is the endpoint of the arc.

CircularSector[ <Point M>, <Point A>, <Point B> ]

.... Creates a circular sector with midpoint M between two points A and B.

How about this adding this command:

CircularSegment[ <Point M>, <Point A>, <Point B> ]

It would create the red area below. Yes, there is a workaround, but IMHO a student should be able to use this command to quickly define and find the circular segment of a circle part... b1081e45b490708a6bb21f6184b9f02a This is one of the few parts of a circle where there is no command at this time. The green triangle is also a circle part but is easy to define with the polygon commands.

I hope the developers will add this command to the command list...

Thank you,

Tony

Files: cap02.png cap03.png

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Comments (6)

acron ● 10 years ago

The attached file shows most of the parts of a circle, many of which GG currently incorporates...

Tony

https://ggbm.at/560995

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slik ● 10 years ago

Hi Tony,

Doesn't CircularArc[ <Midpoint>, <Point>, <Point> ] do what you want when shaded? If you want a different colour border you'll need to add a segment. Or was this the workaround? :)

Simon

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acron ● 10 years ago

No, the command CircularArc[ <Midpoint>, <Point>, <Point> ] is the arc length of the central angle. When shaded it shows the area of a sector, the CircularArc command does not find the area of the sector.

The segment of a circle is the area bounded by a chord and an arc length of the subtended angle (this formula uses radians)

A = 1/2 r^2 (Θ - sin Θ)

Look at the attachment circleParts2.ggb for most definitions and formulas.

Tony d9ef916503e169031591c2da6c46abb2

Files: cap02.png

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slik ● 10 years ago

So you want Area[CircularArc] as a workaround.

I guess you want a tool that creates the circular arc, adds a chord, shades it and outputs the area?

But I agree, a specific in-built tool would be tidier without the extraneous information.

https://ggbm.at/1391001

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acron ● 10 years ago

So you want Area[CircularArc] as a workaround.

But I agree, a specific in-built tool would be tidier without the extraneous information.

Correct a built-in tool is better, especially since most of the other tools already exist.

Thanks for understanding...

Tony

BTW, I do not usually want to use ggt tools as I am still trying to learn them well enough to teach them...Also, if the term is a common term it should be built-in.

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Tedus ● 8 years ago

I know this is an old thread but I wanted to add my support for the comments made by Tony.

As a Circle Segment is such a common circle property it would be fantastic to have it added if possible.

Thanks,

David.

p.s. (If a command does exist now please let me know)

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