Question

If two straight lines are perpendicular to the same line, prove that they are parallel to each other.

Answer 1

Given: $m\perp landn\perp l$
To prove m || n
$\because m\perp l$
$\therefore \angle 1={90}^0$
Similarly $n\perp l$,
$\therefore \angle 2={90}^0$
$\therefore \angle 1=\angle 2$ (each =${90}^0$)
But these are corresponding angles
$\therefore m||n$