The study embraced the interpretive paradigmatic viewpoint. The current study applied the qualitative methodology. The study was cross-sectional because data in the study was collected only once through the Euclidean Geometry Proficiency Test. The data collection technique used in the present study was an open-ended learners' assessment test. A Euclidean Geometry Proficiency Test was used as the starting point towards the acquisition of qualitative data. The study used the Oregon Mathematics Problem Solving Rubric and and Rubric of mathematical adaptive reasoning as its frameworks of analysis of the learners' solutions to the problems.