Let A be the set of all triangles in a plane. Let R be the relation in A defined as R = { ( x , y ) : x is congruent to y }. then R is
Answer & explanation
Correct answer: option 3
For every x ∈ set of triangles
x is congruent to itself ⇒ reflexive
$x≅y⇒y≅x$ (reflexive)
$x≅y,y≅z,x≅z$ (transitive)
⇒ relation is equivalence