[seqfan] Geometry Problem

[Antreas Hatzipolakis]

Also number of nondegenerate triangles that can be made from rods of length
1,2,3,4,...,n. - Alfred Bruckstein
Also number of circumscribable (or escrible) *quadrilaterals* that can be
made from rods of length 1,2,3,4,....,n. - Antreas P.
*Hatzipolakis*
*(*A002623 <https://oeis.org/A002623> Comments)


Another problem:

Which is the number of the nondegenerate triangles that can be made whose
the inradius and the three exradii have lengths from the set
{1,2,3,4,...,n}?

The relation of the inradius r and the exradii r_a, r_b, r_c is:

1/r = 1/r_a + 1/r_b + 1/r_c

Antreas