Chanprom P, Yamsang N, Yamsang W. The Development of Mathematics Learning Activities Using Constructivist Theory on Parallel Lines for Matthayom Sueksa Two Students at Ramkhamhaeng University Demonstration School (Secondary Level) . rpujournal [internet]. 2024 Apr. 30 [cited 2025 Dec. 24];10(1):352-67. available from: https://so03.tci-thaijo.org/index.php/rpu/article/view/277495