Effect of mathematics software GeoGebra mathematics lesson on achievement and Van Hiele levels of geometric of 8th grades in teaching of trigonometry and slope issues

The purpose of this study is to determine the effect of dynamic mathematics software GeoGebra to students? mathematical achievement and to students? Van Hiele geometrical thinking levels in teaching the gains related to trigonometric ratios and slope subjects in 8th grade Math lessons. Research group comprises of 52 eighth grade students, 26 of them is from experimental group and 26 of them is from control group who are studying in a primary school in Hendek, Sakarya in 2011-2012 Academic year. Experimental and control groups are determined according to the results of achievement test and geometrical thinking test. In order to observe the effect of dynamic geometry software GeoGebra, lessons are taught in the light of constructivist learning theory in control group while in experimental group; lessons are taught by computer-aided teaching method in which dynamic software GeoGebra is used. Within this scope, computer-aided teaching materials have been developed by the researcher. This research is an experimental study. The research design is pre-test, post-test control group experimental modal. These are the research findings:1-A significant increase has been observed in the academic achievement of students, using dynamic geometry software GeoGebra in Math lesson than the academic achievement of students, learning mathematics with the traditional teaching method.2-When the academic achievements of students are examined according to the cognitive domain, a significant difference has not been found in the level of knowledge and application stage. But in the comprehension level, there is difference on behalf of the students using GeoGebra.3-According to the retention test that was applied 6 weeks later, Dynamic geometry software has had positive effects on retention.4-The effect of dynamic geometry software GeoGebra to the students? geometrical thinking level was not meaningful (significant).Keywords: Dynamic Geometry Software, GeoGebra, Van Hiele Geometrical Thinking Level, Mathematic, Achievement, Student.