Science, Technology, Engineering, and Mathematics-Based Problem-Based Learning Model for Fifth-Grade Students’ Learning Outcomes in Perimeter and Area of Plane Figures. J. Bs. Edu. R [Internet]. 2026 May 20 [cited 2026 Jun. 8];7(3):161-8. Available from: https://cahaya-ic.com/index.php/JBER/article/view/3042