Practicing Success
In the following figure, AD bisects angle BAC. Find the length (in cm) of BD. |
4 5 9 6 |
4 |
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. |