Man pages matching name math::convexhull::monotonechain in section 3pm:

Math::ConvexHull::MonotoneChain.3pm.en	debian 10 / libmath-convexhull-monotonechain-perl
Math::ConvexHull::MonotoneChain.3pm.en	debian 11 / libmath-convexhull-monotonechain-perl
Math::ConvexHull::MonotoneChain.3pm.en	debian 12 / libmath-convexhull-monotonechain-perl