punctele A, B, C sunt coliniare. Aflati lungimea segmentului AB daca : a)AC =7dm, BC =4dm 3cm b)AC =11dm 3cm, BC =18 dm 8cm c)AC =3dm 7cm 7mm ,BC =2dm 8cm 9mm d)AC =5dm 5cm 5mm, BC =5dm 6cm 7mm DAU COROANA. AJUTOR