BITSAT2024MathematicsSets and RelationsActual
Let R be the relation "is congruent to" on the set of all triangles in a plane is
Options
- AReflexive only
- BSymmetric only
- CSymmetric and reflexive only
- DEquivalence relation
Correct answer
D. Equivalence relation
Step-by-step solution
Let S denote the set of all triangles in a plane. Let R be the relation on S defined by ( ₁, ₂ ) triangle ₁ ₂ : (i) Let any triangle S , we have ₁ ₂ ( , ) R S R is reflexive on (ii) Let ₁, ₂ ~S , such that ( ₁, ₂ ) R , then ₁ ₂ ₂ ₁ ( ₂, ₁ ) R R is symmÄ™tric (iii) Again, let ₁, ₂, ₃ ~S such that ( ₁, ₂ ) R and ( ₂, ₃ ) R ₁ ₂ ₃ ( ₁, ₂ ) R R is transitive. R is an equivalence relation.