triunghiul abc ad bisectoarea unghiului a ab =6 ac=10 bc=8 sa se afle bd dc
dau coroana

Răspuns:
AD/AB=CD/BD
AD/6=(BC-BD)/BD
AD=6(8-BD)/BD
sau
AD/AC=BD/(BC-BD)
AD/10=BD/(8-BD)
AD=10BD/(8-BD)
le egalăm
6(8-BD)/BD=10BD/(8-BD)
6(8-BD)²=10BD²/:2
³64-³16BD+³BD²=5/3BD²
192-48BD-2BD²=0
-192+48BD+2BD²=0
BD= 3,5cm
DC=8-3,5=4,5cm