In the following figure, AD bisects angle BAC. Find the length (in cm) of BD.
Answer & explanation
Correct answer: option 1
According to the concepts
\(\frac{6}{2x\;-\;3}\) = \(\frac{x\;-\;2}{x}\)
⇒ 6x = 2\( { x}^{2 } \) - 4x - 3x + 6
⇒ 6x = 2\( { x}^{2 } \) - 7x + 6
⇒ 0 = 2\( { x}^{2 } \) - 7x + 6 - 6x
⇒ 2\( { x}^{2 } \) - 7x + 6 = 0
⇒ 2\( { x}^{2 } \) - 12x - x + 6 = 0
⇒ 2x(x - 6) - (x - 6) = 0
⇒ (x - 6)(2x -1) = 0
So, x = 6, \(\frac{1}{2}\)
For x = \(\frac{1}{2}\)
BD = \(\frac{1}{2}\) - 2
⇒ -\(\frac{3}{2}\) as the value of a side cannot be negative
So, x = 6
Now,
BD = 6 - 2
⇒ 4 cm
The length of BD is 4 cm.