摘要：In parallel with the development of mathematics and geo metry software and increase in computer hardware at schools; there has been increasing importance attributed to the computer assisted mathematic instruction. This is revealed that the necessity of determining the co mputer assisted instruction to what extent affects students' success. The purpose of this stud y is to examine the effect of computer-assisted geometry teaching on seventh grade students' achievement. It's an experimental research in which pre and post tests are used. Data collected through 22-item geometry achievement test developed by researchers. In experimental group, the courses were taught b y the help of Vitamin Program, reco mmended by Ministry of Educatio n and Microsoft Picture Manager program in information and technology class at school. However; in control group, the method and activities included in the present programme are processed in their own classroom. The data were analyzed via SPSS 16 software, t-test and Ancova was conducted to analyze the data. As a result, this study showed that there is a positive effect of computer assisted instruction on the students' geo metry achievement. Based on this; it is seen that co mputers and educational software in teaching geo metry have positive effect on students' academic achievement.
