In △ABC, the angle bisector AD of ∠A divides side BC. If AB=10 cm, AC=12 cm, and BC=11 cm, what is the length of the segment BD?
Show answer & explanation
Correct answer: A
Explanation
AB = 10 cm
AC = 12 cm
BC = 11 cm
According to the formula:
Angle Bisector Theorem ⇒ BD/DC = AB/AC
BD/DC = 10/12 = 5/6
Let BD = 5x, DC = 6x
BC = BD + DC
11 = 5x + 6x
11 = 11x
x = 1
BD = 5x = 5 cm