The aim of this study was to investigate how the implementation of GeoGebra by teachers who had recently attended a GeoGebra training course, impacts on learner experience and achievement. The study was conducted in four disadvantaged and under resourced schools situated in rural areas of the Mpumalanga Province of South Africa. Despite the curriculum’s encouragement to use educational technology in the mathematics classroom, and evidence of the benefits of such use, literature indicates that most mathematics teachers still struggle with effective technology integration into their classrooms. Within the non-equivalent quasi-experimental design of this study, a quantitative approach was used. The conceptual framework involved the first two levels of Kirkpatrick’s (1996) four level framework. Four Grade 10 classes comprising of 165 learners participated in this research. Data collection involved a questionnaire administered to the experimental group, as well as pre- and post-tests assessing the achievement of the learners regarding the properties of quadrilaterals administered to both the experimental and control groups. Results from the quantitative data analysis showed a significant difference in the mean scores with a mean difference of 6.5 in favour of learners taught with GeoGebra compared to a chalk and talk method. Implementation of and enthusiasm about GeoGebra had a positive influence on learner achievement. Analysis of the questionnaire responses indicated a positive reaction towards the use of GeoGebra in learning about quadrilaterals. Based on the results, it was concluded that GeoGebra as a pedagogical tool can work effectively in deep rural schools where geometry is hardly taught.