A case study: the use of GeoGebra to alleviate learner difficulty in learning the similarity of triangles in a South African grade 9 classroom.

Abstract

The mixed methods study investigated the use of GeoGebra as a dynamic geometry software (DGS) to alleviate the learning similarity of triangles. A mixed methods philosophical framework in the form of an exploratory case study was used to conveniently and purposively select a sample of 60 Grade 9 learners enrolled at Sondelani Full-Service School (pseudonym), a township school in the Pinetown district in KwaZulu–Natal province, South Africa. During this research, GeoGebra and the concept of similarity of triangles were introduced to the participants. Then, participants answered several (Euclidean geometry) Similarity Achievement Test (SAT) questions prescribed by the National Mathematics pacesetter for Grade 9 and 10. A 10-item Likert scale questionnaire intended to elicit participants’ attitudes about GeoGebra and its impact on Euclidean geometry and mathematics was administered to these participants. The questionnaire also included four open-ended items, asking participants to reflect on the application of GeoGebra. The analysis of SAT data revealed that performance was higher after GeoGebra instruction (𝑀 = 22.50) than during traditional instruction, which did not feature GeoGebra (𝑀 = 11.65). Thus, it was found that the use of GeoGebra is an appropriate tool to increase achievement in learning geometry concepts; to promote accuracy, visualization; learner participation; and to create enjoyment and learner interest towards learning mathematics. It is recommended that mathematics teachers need to use GeoGebra for effective teaching and learning of similarity of triangles.