Let T be the set of all triangles in a plane with R is a relation in T...
For reflexive, T1 is congruent to T1
⇒ (T1,T1) Î R For symmetric, (T1,T2) ∈ R ⇒ T1 is congruent to T2 ⇒ T2 is congruent to T1 ⇒ (T2,T1) ∈ R. Hence it is symmetric.
For transitive, (T1, T2) ∈ R ⇒ T1 is congruent to T2 and (T2,T3) ∈ R ⇒ T2 is congruent to T3 which implies T1 is congruent to T3 ⇒ (T1,T3) ∈ R. Hence, it is transitive.
Hence, R is an equivalence relation.
Let T be the set of all triangles in a plane with R is a relation in T...
Equivalence Relation Explanation:
An equivalence relation is a relation that is reflexive, symmetric, and transitive. Let's see how relation R in set T satisfies these properties:
Reflexive:
- For any triangle T1, T1 is congruent to itself (by definition of congruence).
- Therefore, R contains pairs like (T1, T1) for all T1 in T, making it reflexive.
Symmetric:
- If triangle T1 is congruent to triangle T2, then triangle T2 is also congruent to triangle T1 (by the properties of congruence).
- This means that if (T1, T2) is in R, then (T2, T1) must also be in R, satisfying symmetry.
Transitive:
- If triangle T1 is congruent to triangle T2, and triangle T2 is congruent to triangle T3, then triangle T1 is congruent to triangle T3 (by the transitive property of congruence).
- This implies that if (T1, T2) and (T2, T3) are in R, then (T1, T3) must also be in R, meeting the transitive criterion.
Since relation R in set T satisfies the properties of reflexivity, symmetry, and transitivity, it is an equivalence relation.