This study aimed to investigate the effectiveness of smart mechanisms (i.e., personalization, contextualization, and socialization) on geometry learning supported by Smart-UG, a mobile application with the integration of augmented reality (AR) to facilitate authentic learning and provide learners with some features in measuring and applying geometric concepts in a real-world environment. To investigate the impact of the technology with smart mechanisms on student learning achievements (i.e., geometry ability (GA) and problem-solving skill (PSS), we conducted a quasi-experiment with the participation of fifth-grade students (n = 52). They were divided into two groups (i.e., experimental and control group) and carried out two stages of learning activity with an independent experiment which is underpinned by a set of problem-solving activities. Stage 1 aimed to investigate the impact of personalization and contextualization mechanisms, while stage 2 focuses on assessing socialization's impact on geometry learning. The results showed that the experimental group students achieve good performance in geometry measurement and problem-solving compared to those in the control group. It implied that our proposed application with smart mechanisms can benefit learners to improve their geometry understanding and skill. A positive attitude and high intention by the students toward Smart-UG also signify system utilization in the future. Therefore, this study has the potential to be applied in more complex geometry learning with enhanced smart mechanisms.