Answer : An equivalence relation is one which possesses the properties of reflexivity, symmetry and transitivity.

• Reflexivity: A relation R on A is said to be reflexive if (a, a) є R for all a є
• Symmetry: A relation R on A is said to be symmetrical if (a,b) є R è(b, a) є R for all (a, b) є
• Transitivity: A relation R on A is said to be transitive if (a, b) є R and (b, c) є R è (a, c) є R for all (a, b, c) є

Let S be a set of all triangles in a plane.

• Since every triangle is similar to itself, it is
• If one triangle is similar to another triangle, it implies that the other triangle is also similar to the first Hence, it is symmetric.
• If one triangle is similar to a triangle and another triangle is also similar to that triangle, all the three triangles are similar. Hence, it is