Let be the set of all triangles in the Euclidean plane and let a relation on be defined as if is congruent to for all , then is:
(3)
Ans. Equivalence
Explanation:
Each triangle is congruent to itself.
Relation is reflexive.
Suppose
then
Relation is symmetric.
Suppose
and
then
Relation is transitive.
Relation is an equivalence relation.