Abstract
This study investigated the effects of rabometer on students?EUR(TM) achievement in geometry in Pankshin Local Government Area of Plateau State, Nigeria. The study adopted quasi-experimental research design. Four schools were randomly selected from all the schools in the Local Government Area. Two of the schools were used as the experimental group, while the other two served as the control group. The sample for the study comprised of 146 senior secondary one students. The experimental group was taught using rabometer as an instructional material, while the control group was taught without it after the administration of the pre-test. the students in each group were given a post-test. The result showed that the use of rabometer improved students?EUR(TM) achievement in plane geometry and a significant difference in the mean scores of those taught using rabometer and those taught without rabometer. As well as non?EUR??asignificant difference in the mean achievement scores of male and female students and hypothesis three indicated a significant difference in students?EUR(TM) mean achievement scores in private and public schools. It was recommended that rabometer as an instructional material should be made available to schools for teachers to use during teaching/learning of geometry.