Keraton Ngayogyakarta Hadiningrat: A plane geometry learning material sources based on the ethnomathematics approaches.

Ethnomathematics facilitates the relationship between mathematics and culture so that the mathematical potential of a cultural site can be utilized as a source of student learning. The Keraton Ngayogyakarta Hadiningrat (Ngayogyakarta Palace) is one of the royal sites that has a lot of mathematical potential, both from the shape of the building to the ornaments contained in the building. This research is ethnographic qualitative-explorative research with the validity of the data using the triangulation method. Data were collected through observation, interviews, and documentation methods. It was found that geometric shapes such as squares, rectangles, trapezoids, rhombuses, triangles, and circles were found in the wards and buildings in the Ngayogyakarta Palace. These findings can be used to teach the material properties of plane shapes, the area and perimeter of shapes, similarity, and symmetry in school mathematics. [ABSTRACT FROM AUTHOR]