Enhancing Critical Thinking Skills in Geometry through the Guided Discovery Approach with GeoGebra

In this modern era of K-12 curriculum, if students are expected to be knowledgeable and skilled, it is a requirement for the teachers to meet and cope with the necessary skills and competencies for the students to be more competent. This study is developed to investigate the effect of the Guided Discovery Approach (GDA) with GeoGebra on critical thinking skills in ninth-grade geometry students at Baluan National High School during the 2022-2023. Employing a true experimental research design, the study revealed that the student’s level of achievement in critical thinking skills in creating, applying, analyzing, and evaluating both in the conventional and experimental groups increases in mean gain scores of 28.27 and 32.8 respectively. The t-test result further shows a t(28) = 2.70 and a p-value = 0.01 indicating that the GDA with GeoGebra in teaching Geometry significantly improved students' critical thinking. It further reveals a significant increase in post-test scores for the experimental group emphasizing the effectiveness of GDA with GeoGebra. While students moderately accepted GeoGebra, there is no significant relationship between their critical thinking skills and acceptability. The findings underscore the importance of instructional methods in improving critical thinking skills, showcasing the potential of GDA with GeoGebra in Geometry.