toole nimsazre raase A az mosalase ABC barabare 2ab/a+b CosA/2 mishe
hala toole nimsaze raase B , C ro barabar mizarim va dar moadele akhar borhane kholf mizanim
farz mikonim B>C va naTje mide Cos B/2 <Cos C/2
pas dar tasavi ye taraf akidan az tarafe dige bozorgtare ke tanaghoze.
age ravabetesho khastid begid benevisam