Q) In Fig. AD bisects ∠A, AB = 12 cm, AC = 20 cm and BD = 5 cm, determine CD.
∵ AD bisects ∠ A
We know that, according to the angle bisector theorem, the angle bisector of a triangle divides the opposite side into two parts that are proportional to the other two sides of the triangle.
∴ CD = = 8.33 cm
Therefore, length of CD is 8.33 cm.