Physics teaching in Sub Saharan Africa often remains theoretical because of a lack of teaching materials and limited access to teacher training, and evidence on low cost, short term professional development in such fragile contexts is scarce. This quasi experimental study was conducted in ten secondary schools in Mbanza Ngungu, Democratic Republic of Congo, with five schools assigned to an experimental group and five to a control group. The sample included 248 students and ten physics teachers from those schools. Data collection relied on a validated ten item test measuring conceptual, procedural and symbolic dimensions of physics learning, complemented by semi structured teacher interviews. The theoretical framework combined three pillars: the use of low cost didactic materials, situated learning as conceived by Lave and Wenger, and Bandura’s concept of teacher self efficacy. The main results show that students taught by trained teachers significantly outperformed control students on the conceptual dimension (Cohen’s d = 0.49) and the symbolic dimension (d = 1.58), whereas no significant difference was observed in procedural skills. Persistent errors in algebra, unit conversion, and graphical interpretation remained in both groups. Teachers in the experimental group reported higher self efficacy but their teaching practices changed in variable ways across individuals. An implication of these findings is that even short term professional development can improve conceptual and symbolic learning under severe resource constraints, yet procedural fluency likely requires stronger collaboration between physics and mathematics teachers as well as longer or more targeted interventions.