Question

Question No. 107
In triangle ABC, AD is the internal bisector of angle A. If AB = 8 cm, AC = 12 cm and BD = 6 cm, then BC =
a) 12 cm
b)15 cm
c) 14 cm
d)13 cm
answer in 5 min fast​

Answer 1

b) 15 cm

According to Thales Theorem:-

Let DC be x

So,

AB = AC

BD x(DC)

8x = 12 ×6

8x = 72

x = 72 ÷ 8

x = 9

So DC = 9 cm

BD + DC = BC

6 + 9 = 15 cm

So BC = 15cm Answer.