Armiati A, Budi AS. Identifikasi Efektifitas Pembelajaran Trigonometri Kelas X Masa Pandemi COVID 19 Melalui Whatsapp Group. jg [Internet]. 2021Mar.31 [cited 2024Dec.19];6(1):11-7. Available from: https://ojs.umrah.ac.id/index.php/gantang/article/view/2539