A teacher-centered, examination-driven instructional approach emphasizing knowledge of facts and standard methods through drill-and-practice without use of Information and Communications Technology (ICT) is still dominant in Nepalese high schools. In this article, we present a classroom study in which the traditional instructional approach has been replaced by an ICT-rich, student-centered, investigative approach in the context of teaching and learning basic concepts of reflection and rotation. Here, ICT refers to dynamic geometry software. Through a pretest-posttest control and experimental group research design, we compared the effects of both approaches on students' understanding. A test was designed and used for investigating students' alternative conceptions of reflection and rotation. The results showed that the experimental group outperformed the control group and there were indications of a lasting effect. Qualitative analysis indicated that all distinctive aspects of the experimental approach had positive effects on the students' performance and learning experience. This study can also be considered as an evidence-based example of how one can, with limited ICT facilities, still achieve improvements in teaching and learning at a public high school in a developing country.