Question

The angle between the lines $2x-y+3=0$ and $x+2y+3=0$ is

• A. ${90}^{\circ }$
• B. ${60}^{\circ }$
• C. ${45}^{\circ }$
• D. ${30}^{\circ }$

Answer 1

The correct option is A

${90}^{\circ }$

Let $m_1$ and $m_2$ be the slope of the line $2x-y+3=0$ and $x+2y+3=0$ respectively.

Let $\theta$ be the angle between them.

Here, $m_1=2$ and $m_2=-\frac{1}{2}$

$\therefore m_1{m}_2=-1$

Therefore, the angle between the given lines is ${90}^{\circ }$