Show that the relation `R` , defined on the set `A` of all polygons as `R={(P_1,\ P_2): P_1` and `P_2` have same number of sides}, is an equivalence relation. What is the set of all elements in `A` related to the right angle triangle `T` with sides 3, 4 and 5?

Explanation

`R=\{(P_{1}, P_{2}): P_{1}`. and `P_{2}` have same the number of sides `\}`



`R` is reflexive since `(P_{1}, P_{1}) \in R` as the same polygon has the same number of sides with itself.




Let `(P_{1}, P_{2}) \in R`.




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