Q. The angle between the line joining the points $(1,\ - 2),\ (3,\ 2)$ and the line $x + 2y - 7 = 0$ is
A) $\pi$
B) $\pi/2$
C) $\pi/3$
D) $\pi/6$
Explanation
(b)
Slope of the given lines are
$m_{1} = \frac{2 + 2}{3 - 1} = 2\ and\ m_{2} = - \frac{1}{2}$
$Now,\ \ \ m_{1} \times m_{2} = 2 \times \frac{- 1}{2} = - 1$
$\therefore$ Lines are perpendicular, so angle is $\frac{\pi}{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.