Completed convex hull.

README.md

@@ -1458,9 +1458,10 @@ Some of mine (I already may know answer to but want their opinion or team perspe
     - [x] Finding minimum cost: https://www.youtube.com/watch?v=2ACJ9ewUC6U
     - [x] Finding maximum value: https://www.youtube.com/watch?v=8AA_81xI3ik
 
-- [ ] **Geometry, Convex hull**
-    - [ ] Geometric Algorithms: Graham & Jarvis - Lecture 10: https://www.youtube.com/watch?v=J5aJEcOr6Eo&index=10&list=PLFDnELG9dpVxQCxuD-9BSy2E7BWY3t5Sm
-    - [ ] Divide & Conquer: Convex Hull, Median Finding: https://www.youtube.com/watch?v=EzeYI7p9MjU&list=PLUl4u3cNGP6317WaSNfmCvGym2ucw3oGp&index=2
+- [x] **Geometry, Convex hull**
+    - [x] Graph Alg. IV: Intro to geometric algorithms - Lecture 9: https://youtu.be/XIAQRlNkJAw?list=PLFDnELG9dpVxQCxuD-9BSy2E7BWY3t5Sm&t=3164
+    - [x] Geometric Algorithms: Graham & Jarvis - Lecture 10: https://www.youtube.com/watch?v=J5aJEcOr6Eo&index=10&list=PLFDnELG9dpVxQCxuD-9BSy2E7BWY3t5Sm
+    - [x] Divide & Conquer: Convex Hull, Median Finding: https://www.youtube.com/watch?v=EzeYI7p9MjU&list=PLUl4u3cNGP6317WaSNfmCvGym2ucw3oGp&index=2
     
 - [x] Discrete math (see videos below)