The Weaknesses of Euclidean Geometry: A Step of Needs Analysis of Non-Euclidean Geometry Learning through an Ethnomathematics Approach

Non-Euclidean geometry is a complex subject for students. To provide a rationale for the need for Non-Euclidean geometry learning, analyzing the weaknesses of Euclidean geometry is necessary. The starting point of learning must be close to students' local minds and culture. The purpose of this study is to describe the weaknesses of Euclidean geometry as a step in analyzing the needs of Non-Euclidean geometry learning through an ethnomathematics approach. This research uses qualitative descriptive methods. The subjects of this study were students of Mathematics Education at State Islamic University (UIN) Fatmawati Soekarno Bengkulu, Indonesia. The researcher acts as a lecturer and the main instrument in this research. Researchers used a spatial ability test instrument to explore qualitative data. The data were analyzed qualitatively descriptively. The result of this research is that there are two weaknesses of Euclidean geometry, namely Euclide's attempt to define all elements in geometry, including points, lines, and planes. Euclide defined that a point as one that has no part. He defined a line as length without width. The words "section", "length", and "width" are not found in Euclidean geometry. In addition, almost every part of Euclide's proof of the theorem uses geometric drawings, but in practice, these drawings are misleading. Local culture and ethnomathematical approaches can be used to design teaching materials and student learning trajectories in studying Non-Euclidean geometry