Mathematics

Problem

13. Show that the relation R defined in the set A of all polygons as

\mathrm{R}=\left\{\left(\mathrm{P}_{1}, \mathrm{P}_{2}\right)\right.

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 ?