The purpose of this research is to develop worksheet based on guided discovery on the solid figure material for class VIII students of SMPN 1 Sungguminasa Gowa regency is valid, practical, and effective. The type of research is research & development with reference to the ADDIE development model which includes 5 stages, namely: the analysis phase, design, development, implementation, evaluation. The subjects in this study were students of class VIII.D SMPN 1 Sungguminasa Kab. Gowa numbered 35

more »

... ople. The instruments consisted of the worksheet validation sheet, the worksheet practicum observation sheet, the student and teacher response questionnaires, the student and teacher activity observation sheet, and the students' mathematics learning outcomes test. The research results show that 1) the validation results from the experts stated that the average value of all components of 130 worksheet eligibility was 3.1 with a valid category, (2) the average for all aspects of observing the worksheet's implementation was 1.24 with a partially implemented category and the average percentage of all aspects of student questionnaire responses was 71.85% in a positive category and the teacher's questionnaire response was 83.89% in a positive category so it is categorized as practical, (3) the average percentage of student activity for the whole learning meeting was 64.80% are in good category and the activities of teachers in managing the learning amounted to 3.76 in good category and the result of mathematics learning outcomes obtained that there are 25 students (71.43%) out of 35 students have achieved a minimum score of 75. So, it can be concluded that the worksheet based on guided discovery in solid figure material for eighth-grade students of SMPN 1 Sungguminasa Gowa regency has met the criteria of validity, practicality, and effectiveness.