# Equations of Straight line making an acute angle with other line.

It's written in a question to find the equations of the two straight lines.

Question: Find the equations of the two straight lines passing through $(2, -1)$ and making acute angles of $\pi/4$ radians with the line $6x+5y=0$.

But when I solve it I get just one equation: $11x-y-23=0$. How to get other equation?

If both acute angles are $\pi/4$ radians, and the whole triangle of course has total angle measure of $\pi$ radians, then the third angle is $\pi/2$ radians. That's a right angle. Therefore the two lines are perpendicular to each other. I trust you can infer the rest...