In a triangle ABC, AD is the angle bisector of angle A. If AB = 8.4 cm and AC = 5.6 cm and DC = 2.8 cm, then the length of side BC will be :
Answer & explanation
Correct answer: option 3
⇒ According to the concept,
⇒ \(\frac{AB}{AC}\) = \(\frac{BD}{DC}\)
⇒ \(\frac{8.4}{5.6}\) = \(\frac{BD}{2.8}\)
⇒ \(\frac{8.4}{2}\) = BD
⇒ 4.2 = BD
So, BD + DC = BC
⇒ BC = 4.2 + 2.8 = 7 cm
Therefore, the length of BC is 7 cm.