If, l, m, n are three lines such that l||m and n⊥ l, prove that n⊥ m.
Given that,
l ‖ m and n perpendicular to m
Since, l ‖ m and n intersects them at G and H respectively
Therefore,
∠1 = ∠2 (Corresponding angles)
But, ∠1 = 90o as n is perpendicular to l
Therefore, ∠2 = 90o
Hence, n is perpendicular to m.