ANALYTIC GEOMETRY PRESENTED BY GUO CHENG GUANG and GUO CHENGXI(01-08)

Prove Heron's Formula or Hero's Formula A=sqrt(s(s-a)(s-b)(s-c)), where a,b and c are side lengths of triangle, s=(a+b+c)/2.

ANALYTIC GEOMETRY PRESENTED BY GUO CHENG GUANG and GUO CHENGXI(01-08,S/N: 8) Presented By Guo Cheng Guang (aged 11) and Guo Chengxi (aged 8) in English. Lessons In Mathematics and Science (Physics, Chemistry and Biology) From Primary to University Presented By Guo Cheng Guang and Guo Chengxi In English. Your comment or suggestion is very much appreciated. https://www.youtube.com/channel/UC2dG5T9SJkUFTy-h0KbVbkw