Can Any software do this? part 2

**steve last** · 10 April 2006, 05:58 PM

I posted a question some time ago in the 3D forum about a particular problem, and having drawn a blank with my previous question despite lots of helpful comments from forum members I’m going to make the question much simpler.

Can anyone point me to a graphics package, or to a software author (amateur or pro) who could devise a simple a simple utility, which would perform the following task. This simply mimics one of the most basic tasks a seven year old can do with a pencil and compasses……..

With a scaled grid showing:
Mark points A and B on a baseline
Select centre A, enter value x and draw arc radius x
Select centre B, enter value y and draw arc radius y
Mark point C at selected intersection of arcs
Delete arcs.

I can't find a way to do this with Xara without it being far too clumsy for repeated use which is what I need which must involve is a minimum number of steps, as outlined above.

Steve Last

**tonylondon** · 11 April 2006, 02:25 PM

Not sure I understand this. Why don't you use circles at A and B?
Tony

**lau3** · 11 April 2006, 04:10 PM

AutoCAD (LT or full version) can do this.

In a differnet "ballgame", you can script After Effects to draw things like this based on math formulas (radius, pi, center point, etc.) but its "goal" is of a different nature.

Hope this helps.

Milton

**Peter Clifton** · 11 April 2006, 08:13 PM

If I read the question correctly, you are constructing a triangle.

This is the geometer's method for constructing a triange when given the dimensions of three sides.

One of my first adventures into programming involved triangles and their construction. Its not quite what you are looking for, but on my web site (link in my signature) is a CorelScript program for Triangle Construction in Corel Draw that will draw a triange given

the dimensions of three sides (in your case the Base AB, the radius of the first circle, the radius of the second circle) also called SSS

or an Angle subtended by two known sides also called SAS

or any two angles and one side also called AAS

Also during my investigations I came across a program called The Geometer's Sketchpad that you might find interesting.

HTH

Peter

**steve last** · 20 April 2006, 11:51 AM

Peter, Lau 3, Tony, apologies for apparently ignoring your replies, I was out of communication for a few days.
"If I read the question correctly, you are constructing a triangle." Yes and no. Yes I am starting by making a triangle, but I do not want to construct triangle as an object. I want locate point C and subsequently points DEFG etc., which I can then join to make an irregular multi-sided shape.

"Why don't you use circles at A and B?" Well I can of course but unless I am missing something extremely basic to do that I have to use the following process

Mark baseline with points A and B on my main layer

change to a new "construction" layer

draw the circle by:
select ellipse
drag to create an ellipse
cursor to width and enter twice the radius r1
tab, enter twice the radius - I now have a circle of right radius
try to align centre of circle over baseline point A - centre isn't marked
repeat for r2 and baseline point B
change back to main layer
mark chosen intersection somehow - maybe with something like another very small circle?
change back to construction layer and select circle centred on A
change width and height again, do the same for B, change back to main layer and mark intersection again.
repeat etc........
finally delete circles.

This is far too laborious and anyway at the end of it I still only have approximations because my markers are the centres of the tiny circles which were located by judgement anyway. and can't be joined as such without another layer and more guesswork.

Will take a look at the Geometer's sketchpad though
Thanks
Steve

**Scotty** · 20 April 2006, 01:46 PM

I believe I saw a program "Sketch" ('cAD 'a drafting program used by my brother-in-law for teaching school, it is a simple program but only output to Dxf format but that was in the 80's.
where you would find a copy now I don't know.
Jim

**pauland** · 20 April 2006, 04:12 PM

Steve, if you had such a program to do as your first post, what use would it be? What would you do with it? is it just simply calculating the position of point C that interests you?

Paul

**Egg Bramhill** · 20 April 2006, 06:16 PM

Steve
A great program for this type of graphic creation is Logo. Unfortunately a search on the web for 'logo' brings up many sites for logo creations.

Here is a link that shows some of the programs capabilities.

I'm sure if you do a bigger search you'll be able to find a free download version. Try 'turtle logo' in the search.

Here's a free download link. I'm not sure it suits your needs but if you delve into it it's great fun.

Here's another that looks more promising. I suggest you download the Tutorial kit. It has a set of videos showing you the very Basic use of the program.

Egg

**jamesmc** · 22 April 2006, 02:50 AM

heh, I remember Logo. It came out with the Commodore 64 (and others)during the 80s. About the same time, the concept of object oriented programming came out (OOP) and Logo sort of died on the vine to the masses.

**jamesmc** · 22 April 2006, 02:57 AM

Originally Posted by steve last

I posted a question some time ago in the 3D forum about a particular problem, and having drawn a blank with my previous question despite lots of helpful comments from forum members I’m going to make the question much simpler.

Can anyone point me to a graphics package, or to a software author (amateur or pro) who could devise a simple a simple utility, which would perform the following task. This simply mimics one of the most basic tasks a seven year old can do with a pencil and compasses……..

With a scaled grid showing:
Mark points A and B on a baseline
Select centre A, enter value x and draw arc radius x
Select centre B, enter value y and draw arc radius y
Mark point C at selected intersection of arcs
Delete arcs.

I can't find a way to do this with Xara without it being far too clumsy for repeated use which is what I need which must involve is a minimum number of steps, as outlined above.

Steve Last

What you're saying is thatyou want a program that acts like a compass and a T-square on graph paper.

By searching on google with the following terms:
(compass math programs software)
I found many compass/ruler programs. Not sure if any have grids, but if they don't try this screen ruler (very versatile.) It can provide a screen grid over any program and is fantastically useful.

Name of the program is Meazure(freeware.)