The study determined the effects of Geogebra on pre-service teacher's achievement and perception in circle theorems. The study was carried out in Evangelical Presbyterian (E.P.) College of Education, Bimbilla. Three research questions were formulated to guide the study. A sample size of 88 pre-service teachers (PSTs) was used. The control and experimental groups had 45 and 43 pre-service teachers respectively. The study used a quasi-experimental design. Data were collected from the subjects and analyzed quantitatively using SPSS version 18 on the close-ended questionnaire and the achievement pre-test and post-test. The pretest and post-test were analyzed using an independent sample t-test while the perception questionnaire used percentages, mean, and standard deviation in the analysis. Results from the study revealed that students taught circles theorem with Geogebra teaching strategy achieved a higher mean score than those taught through the conventional method with large effect size. The experimental group showed a positive interest in the Geogebra teaching strategy of teaching circles. The paired sample t-test also confirmed that the experimental group gained a mean difference of 9.83 in post-test with a large effect size too. The study recommends the integration of Geogebra into the teaching of circle concepts and theorems at the colleges of education in Ghana.

Keywords : Geometry, Circle theorem, Geogebra, Experimental group, Pre-service teachers, Control group