tanA=BC/CA=5/7
tanB=CA/BC=7/5
sinA=BC/AB=5/[根号(5*5+7*7)]=5/根号74
sinB=CA/AB=7/[根号(5*5+7*7)]=7/根号74
cosA=CA/AB=7/[根号(5*5+7*7)]=7/根号74
cosB=BC/AB=5/[根号(5*5+7*7)]=5/根号74
tanA=BC/CA=5/7
tanB=CA/BC=7/5
sinA=BC/AB=5/[根号(5*5+7*7)]=5/根号74
sinB=CA/AB=7/[根号(5*5+7*7)]=7/根号74
cosA=CA/AB=7/[根号(5*5+7*7)]=7/根号74
cosB=BC/AB=5/[根号(5*5+7*7)]=5/根号74