C-14-Q043mediumsingle_mcqIn △ABC\triangle ABC△ABC, AB=6AB = 6AB=6, AC=4AC = 4AC=4, BC=10BC = 10BC=10. ADADAD bisects ∠A\angle A∠A, meets BCBCBC at DDD. Then BD=?BD = ?BD=?a444b555c666d101010ব্যাখ্যাBy the Internal Bisector Theorem, BD:DC=AB:AC=6:4=3:2BD:DC = AB:AC = 6:4 = 3:2BD:DC=AB:AC=6:4=3:2. So BD=33+2×BC=35×10=6BD = \dfrac{3}{3+2} \times BC = \dfrac{3}{5} \times 10 = 6BD=3+23×BC=53×10=6.