Herlina Br Nainggolan and Pandi Barita Nauli Simangungsong 2025. Comparison and Evaluation of Euclidean Distance and Arccosine Distance in Adaptive K-Means Clustering Algorithm for Penguin Species Clustering. Journal Of Data Science . 3, 02 (Aug. 2025), 69–78. DOI:https://doi.org/10.58471/jds.v3i2.6890.