annie9911 New member Xu 0 30/8/10 #1 bai 1: chung minh trong tam giac ABC bat ki ta co a=r(cotB/2 + cotC/2). bai 2: goi H la truc tam tam giac ABC. chung minh rang 3 duong tron ngoai tiep tam giac HBC, HCA, HAB co cung ban kinh voi duong tron ngoai tiep R
bai 1: chung minh trong tam giac ABC bat ki ta co a=r(cotB/2 + cotC/2). bai 2: goi H la truc tam tam giac ABC. chung minh rang 3 duong tron ngoai tiep tam giac HBC, HCA, HAB co cung ban kinh voi duong tron ngoai tiep R
conngan23 New member Xu 0 30/8/10 #2 https://diendankienthuc.net/diendan...toan-lien-quan-den-phep-doi-xung-tam-voi.html link bài 2 bạn có thể kham khảo
https://diendankienthuc.net/diendan...toan-lien-quan-den-phep-doi-xung-tam-voi.html link bài 2 bạn có thể kham khảo