Esmukhan Жанузак, and Kuspekov Каирбек. “Theorems on Perpendicularity of a Line and a Plane”. Рroblems of engineering and professional education 7, no. 7 (January 25, 2023): 26. Accessed April 8, 2025. https://bulprengpe.enu.kz/index.php/main/article/view/292.