Hope I can do the explanation justice, and that someone cna help.

I'm looking for a chart that will show three values, as follows:

The chart will take the form of a triangle. In each of the corners

are the values 'A', 'B' & 'C'. Each of the sides represent avalue

from 0 to 100. The idea is to take the data below and plot it into

the graph as follows:

A - 70

B - 60

C - 55

A line will go from corner A onto side BC, and stop at the indicator

for 70. A line will go from corner B onto side CA, and stop at the

indicator for 60. Finally, a line will go from corner C ontothe side

AB and stop at the indicator for 55. The aim is then to identify

where the three lines merge, if at all.

Is this possible, in Excel 2003, and if so how?

TIA

Duncs

Is ABC equilateral?

By "identify" do you mean by eye or by calculation?

Is this a standard chart used in some analysis and usually drawn by

hand?- Hide quoted text -

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The triangle is equilateral, with all sides showing a uniform rangeof

0 to 100.

Preferably, I'd like the graph to plot the three lines and see

visually where the lines converge. However, to get a number

representing the intersection point of the three lines would be good.

The graph is currently charted by hand, but there are approximately12

of them at the moment all representing different areas of a project,

and then copied over multiple projects--with different values.

The ability to generate the graph automaticall from the data would be

a great help.

Can it be done?

Duncs- Hide quoted text -

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I'm sure it can be done. There is no standard chart. You would have

to construct your own or get an expert to do it.

In principle there are no real problems. The vertices are, say, A

(0,0), B (50, 86.6) - [that's 50*SQRT(3)] and C (100,0) so you have

the starting points of your three cutting lines. Opposite each vertex

we have a point a certain percentage along the opposite line. An

example. To find the point X which is 70% of the way along BC

starting from B is to combine 70% of C and 30% of B. Note that the

percentage is applied to the "opposite" end. You are closer to C so

you take more of C.

Think of it as 70%*(100,0)+30%*(50, 86.6) although that doesn't quit

make sense. The point X is (70%*100+30%*50,70%*0+30%*86.6) = (85,

26.0) So now you have a line from A to X. Repeat with the othertwo

lines. You now have start and end of each of three sides and three

"%" lines. Plot away.

If you need scales, make separate a separate data series for each side

and label the points using the chart labeller addin.

Here is something related which isn't what you want but the idea is

probably worth looking at.

http://www.lboro.ac.uk/research/phys-geog/tri-plot/index.html
A mathematical measure of the closeness of the intersection is

possible too but is more complicated and can wait until you have this

going.

Derek- Hide quoted text -

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