Q86 / 160 · TS EAMCET 2007 · Mathematics
The angle between the line joining the points $(1,-2),(3,2)$ and the line $x+2 y-7=0$ is
- A$\pi$
- Correct answerB$\pi / 2$
- C$\pi / 3$
- D$\pi / 6$
Solution
Given the line joining the points $(1,-2)(3,2)$ and $x+2 y-7=0$.
Slope of the lines are
$m_1=\frac{2+2}{3-1}=2 \quad$ and $\quad m_2=-\frac{1}{2}$
Now, $m_1 \times m_2=2 \times \frac{-1}{2}=-1$
$\therefore$ Lines are perpendicular, so angle is $\frac{\pi}{2}$.
Hence, the correct answer is option: 'B'.