When distinguishing between the three quadrilaterals, I assert that “every quadrilateral wishes they were born as a square because it represents absolute perfection in the quadrilateral family.”
Then continuing… “It would suck to be born like this quadrilateral [draw some ugly scalene quadrilateral on the board].
“He has nothing going for him. No congruent sides, no congruent angles, nothing parallel, nothing special about his diagonals. Nothing.”
When comparing a square to a rectangle and rhombus, I use the following analogy: “If a rhombus and rectangle got married and had a kid, it would be a square. The rectangle may say to the rhombus: ‘With your sides and my angles, we could make beautiful babies.'”