Question

If each of the two lines is perpendicular to the same line, what kind of lines are they to each
other?

Answer 1

Let AB and CD be perpendicular to MN

`∠`ABD = 90°       [ AB ⊥ MN ]             ....(i )

`∠`CON = 90°      [CD ^ MN ]             ....(ii)

Now,

`∠`ABD = `∠`CDN = 90°                 [From (i) and (ii)]

∴AB parallel to CD,

Since corresponding angle are equal