These all algorithms are interactive. Some of them can be modified and re-run again by clicking upper right part of the code part. Visit Convex Hull and Smallest Enclosing Circle first. They are well documented algorithms for modifying.
Well know Convex Hull problem is coded here. It is very basic algorithm in Computational Geometry.
Smallest Enclosing Disk
Problem of finding smallest circle that contains all of a given set of points in the Euclidean plane.
Polygon P in the plane is called monotone with respect to a straight line L. What is this L?