Online Course Discussion Forum

not sure how to prove p14 (winter camp geometry blue)

 
 
XuIris的头像
not sure how to prove p14 (winter camp geometry blue)
XuIris - 2021年01月13日 Wednesday 13:32
 
any suggestions would be helpful. thanks
 
WangDr. Kevin的头像
Re: not sure how to prove p14 (winter camp geometry blue)
WangDr. Kevin - 2021年01月13日 Wednesday 15:46
 

I will give two possible methods.  First, use Law of Sines to and trigonometry identities.

Second: it is easy to find out about the angles A, B, and C.  Then expand the triangle into a regular heptagon (7-sided polygon).  Then apply Ptolemy's Theorem.