Assume, you want to cluster $7$ observations into $3$ clusters using K$-$Means clustering algorithm. After first iteration clusters, C$1,$ C$2,$ C$3$ has following observations:

C$1$: $\{(2,2),(4,4),(6,6)\}$

C$2$: $\{(0,4),(4,0)\}$

C$3$: $\{(5,5),(9,9)\}.$

What will be the centroids of C$1,$ C$2,$ and C$3?$