Abstract :
One of the important components in learning three-dimensional material that is often difficult for students to
understand is determining the distance between two points in space. The purpose of this research is to develop
a learning approach that can help students understand the concept of the third dimension by using the RME
methodology supported by Geogebra. This research uses a three-stage research design proposed by
Gravemeijer & Cobb. The data used for analysis is descriptive qualitative. Students of Class XII MIPA 3
SMAN 3 Semarang were involved in this research. Interviews, pre-test and post-test, student assignment
results, class activities and group projects, and observation were the methods of data collection. The results of
this study indicate that the learning trajectory consisting of three activities is expected to provide motivation
and inspiration for teachers in teaching, especially in conveying the concept of the third dimension to students.
Keywords: Realistic Mathematics Education, Geometry, Third Dimension, Point to Point Distance, Geogebra
Assisted