If you are referencing the region at least, then the following algorithms could potentially be useful.
Triangle
linear (.. O (n)) , ,
. . , , , Springer, . 1-16, 2014 .
, :
J. , . , . , . , , Journal of Algorithms, vol. 7, . 2, pp. 258-269, 1986 .
: .
++ :
https://github.com/IceRage/minimal-area-triangle
(3.0) OpenCV.
:
G. , , (ESA), Springer, pp. 325-338, 1999.
++ :
http://www.inf.ethz.ch/personal/gaertner/miniball.html.