Add reference and distance formulas

readme.md

@@ -133,3 +133,13 @@ Au lieu d'afficher directement le résultat final de votre implémentation de l'
 - [https://towardsmachinelearning.org/k-means/](https://towardsmachinelearning.org/k-means/)
 
 - [https://vitalflux.com/elbow-method-silhouette-score-which-better/](https://vitalflux.com/elbow-method-silhouette-score-which-better/)
+
+
+- Figure 1 : [https://stats.stackexchange.com/questions/146339/what-does-cluster-size-mean-in-context-of-k-means](https://stats.stackexchange.com/questions/146339/what-does-cluster-size-mean-in-context-of-k-means)
+
+# 
+
+$$d(a, b) = \sqrt{\sum_{i = 1}^{n}(a_i - b_i)^2}$$
+
+
+$$d(a, b) = \sum_{i = 1}^{n}|a_i - b_i|$$
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