Published Paper Details:

Abstract There is strong evidence in mathematics education literature that students benefit extensively from Geometry concepts of mathematics in daily life. The benefits include developing an advanced level of mathematical thinking, spatial reasoning and conceptual understanding. The purpose of this study was to investigate students understanding on geometry course and to give effective method of teaching. The sample consisted of 36 students in ML11 section of first year students in KCTE 2019.The sampling technique was used two stages sampling, in the first stage section ML11 selected purposely and the two groups experimental group and control group of the study selected randomly by using Microsoft excel. The collected data were analyzed descriptively and by inferential statistics using software package social science students SPSS (20.1). The reliability of research questionnaire was tested by cronbach�s alpha (0.641) which is reliable, and validated by experienced mathematics teachers. This study followed by pre-test and post-test for both experimental and controlled group. Conceptual understanding of the students on topics of geometry was measured through open-ended questions and some findings were obtained. The intervention given was teaching with involving GeoGebra software instruction for experimental group, And teaching geometry without involving GeoGebra software instruction for the controlled group. Statistical analysis is conducted by firstly testing the normality of the data, by using Kolmogorov Smirnov test data were distributed normally. Then the homogeneity was checked and result shows that data are not homogein due to this t-test was executed. Data were analyzed with an independent samples t-test on gain scores for control and experimental groups. In the conceptual understanding test, the gain scores of the experimental group were found to be 0.42 standard deviations higher than that of the control group on the average. Therefore from this result the researcher concluded that teaching with GeoGebra may be an effective tool for teaching Geometry concepts.