I was given some points to calculate the convex hull. So when I try to find that on internet I also saw that a question which has asked what is the difference of convex hull and convex polygon. According to my knowledge convex hull is the set of points in convex set and polygon is the representation of them in 2D plane. (PLEASE CORRECT ME IF IM WRONG)
However my given points are below and how I tried do calculate convex hull is given below.
$P1=(1,1) , P2=(2,2)$ , $P3=(1.5,3)$ , $P4=(2.5,5)$ , $P5=(3,4)$, $P6=(3,2)$ , $P7=(5,4)$ , $P8=(6,2)$ , $P9=(4,1)$
By plotting them in 2D space and going to each point, tried to draw lines to each remaining points and tried to find the internal angle less than 180 while being the largest one among other angles.
I'm not 100% sure that my method is correct. So if someone can please tell me how to find the convex hull by hand (not with programs) and tell me the difference between convex hull and polygon (if my interpretation is wrong).