This problem is connected with
my post to geometry-puzzles newsgroup,
from which I present here some text:
Take triangle ABC with all acute angles,
with vertices A, B, C and sides a=BC, b=CA, and c=AB, see the Figure:
For any given triangle ABC with all acute angles,
the triangle with vertices I, K, L
is unique (and easy to construct).
Also the
circular triangle,
with the same vertices I, K, L but with sides IFK,
KDL, LEI is unique (and easy to construct).
Now assuming that we know side lengths of triangle ABC:
1. Find the area (and perimeter) of the triangle IKL.
2. Find the area (and perimeter) of the circular triangleIFKDLEI.
First, consider the case of the regular triangle ABC,
the case shown in the above Figure.
In this case triangle IKL is also regular and problem is much more easier.
See here, but better to try yourself!
N/A