Question: How do I find the coordinates, using the with (geometry) package, of the base of an altitude?

I'd like to find the harmonic mean of the lengths of the three altitudes of a triangle.  I believe this to be equal to the radius of the incenter of the triangle.  I haven't used the geometry package  much, but notice it has some interesting features like Harmonic mean. (Incidentally, it has a vertex, and vertices command, but these don't seem to be recognised in Maple 7 - not even in the Help section.)  I would normally tackle thissue  problem using coordinate geometry, and give a diagram of the triangle using the plots [display] command.  Id like some advice about the interactivity of commands in geometry and plots packages eg  can I find the coordinates of the base of an altitudemail using the geometry package?  There is an altitude command which gives the àltitude's equation.  For this the coding would be

:triangle(ABC, [point (A,0,0),point (B,,2,0), point (C,1,3)]:

altitude (hA1,A, ABC);

detail (hA1);

   I think I have answered my own question!  I see there is a DefinedAs command which would give me the coords.   Am I correct in thinking the geometry package is the best method of doing this.  Later I was hoping to display animation, to see how the Harmonic mean changes with varying different triangles.

Thanks for reading this and Happy New Year.

David