This study has been conducted in order to define the effects of the instructional use of the "Geometer's Sketchpad" (GSP) worksheets on the circles through the help of a computer supported with a video projector in the 7th grade of a primary school. This is an experimental study and the three classes have been chosen from the 7th grade of The Private Çakır Primary school in Bursa City for the implementation of the "Computer Assisted Geometry Instruction". At the beginning, it was demonstrated to the students in the first two hours. Following that, the program with the GSP worksheets on the circles prepared by the researcher were instructed in math class in the classroom mounted with a computer and a video projected screen. At the end of the program, 15 raw multiple-item test questions on circles were asked and their performance scores on circles were obtained. Thus, their geometry grades earlier computed were compared and accounted for statistically. Furthermore, the survey sheets handed out to the audience composed of several teachers and students were collected. The findings of the study are as follows: 1- Computer Assisted Geometry Instruction has made some noteworthy contributions to the betterment of the students with unsatisfactory levels. ~2' Thë të~àchë^ accounted from the survey report that the class was interestingly taught, the animations were used, the class was not monotonous and boring, the details on the topic were instructed visually instead of direct memorization. 3- As for the negative ones; the subtopics were taught rapidly, less examples were solved, the students were not active as expected.