# Equation of Lines Parallel to Axes

(i) Equation of a Line Parallel to the X-Axis:
Consider that $l$ is the straight line which is passing through the point $A\left( {0,b} \right)$ and is parallel tothe $X$-axis because this point lies on the $Y$-axis and any point on the Y-axis whose values of $x$ are zero.

Then the equation of a line parallel to the X-axis is given by
$\boxed{y = b}$

(ii) Equation of a Line Parallel to the Y-Axis:
Consider that $l$ is the straight line which is passing through the point $B\left( {a,0} \right)$ and is parallel to the $Y$-axis, because this point lies on the $X$-axis and any point on the X-axis whose values of $y$ are zero.

Then the equation of a line parallel to the Y-axis is given by
$\boxed{x = a}$