Multiple choice

In triangle ABC, AD is angle bisector of ∠BAC. If AB = 2.8 cm., AC = 4.9 cm. and CD = 2.1 cm., what is length of BD?

  1. 0.8 cm.

  2. 1.0 cm.

  3. 1.2 cm.

  4. 3.7 cm.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

By the Angle Bisector Theorem, the ratio of the sides containing the angle equals the ratio of the segments created on the opposite side: AB/AC = BD/CD. Substituting: 2.8/4.9 = BD/2.1, which gives BD = (2.8 × 2.1)/4.9 = 1.2 cm. The other options do not satisfy this geometric relationship.

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