"We learn by doing and by thinking about what we are doing." (John Dewey) In this article, we shall present findings that describe the degree to which metacognitive orientation contributes to the study of the geometry the plan in boys compared to girls in 9th grade of middle school. The geometry study process does not only involve knowledge but also high thinking abilities. Beyond the knowledge of definitions and sentences, the students are required to write a full, precise, and logically constructed proof, as well as to show the validity and its correctness. In this article, we shall present a model of metacognitive orientation aiming to develop higher-order thinking skills in geometry. We built and applied the model to 9th-grade students. Since students experience difficulties in the study of geometry, the development of a structured study process is required. Numerous studies clearly show that the study process involving metacognitive orientation improves their study ability and deepens their understanding of the topic in question. The question that we addressed was to what extent the metacognitive orientation in geometry impacted boys in comparison to girls? In this study, we shall present data according to which metacognitive learning explicitly benefits girls more than boys. Nevertheless, as a modular model, it allowed every student of both sexes to strengthen the weak aspect and to overcome blockades inhibiting the learning process.