Question

The angle between the line joining the points $(1,-2),(3,2)$ and the line $x+2 y-7=0$ is

• A. 0
• B. $\frac{\pi}{4}$
• C. $\frac{\pi}{2}$
• D. $\pi$

Answer 1

Answer: (C)

Slope of line passing through $(1,-2)$ and $(3,2)$ is
$m_{1}=\frac{2+2}{3-1}=2$
Slope of the line $x+2 y-7=0$
$m_{2}=-\frac{1}{2}$
Now, $m_{1} m_{2}=2 \times \frac{-1}{2}=-1$
$\therefore $ Angle between the line joining the points
$(1,-2)$ and $(3,2)$ and the line $x+2 y-7=0$ is
$\frac{\pi}{2}$.