Let L denote the set of all straight lines in a plane. Let a  relation R be defined by αRβ⇔α⊥β,α,β∈L. Then, R is

Here, αRβ⇔α⊥β∴α⊥β⇔β⊥αHence, R is symmetric One line is not perpendicular to it self, so that R is not reflexive Suppose (L,M), (M,N) are ordered pairs of R, it means L is perpendicular to M and M is perpendicular to N it does not implies that L is perpendicular to N, so that (M, N) does not belongs to Rso that R is not transitive