Why is a square a rhombus but a rhombus not a square?

Answer 1

A square is a special kind of rhombus in which all angles are equal. A rhombus may or may not have all angles equal, so a rhombus does not have to be a square. On the other hand, any figure with four equal sides is a rhombus and all squares have four equal sides so every square is a rhombus.

Other examples of the same situation.Some US Coins are dimes. So every US dime is a coin, but not every coin is

a US dime.

Some cars are Chevy Volts. So every Volt car is a Chevy, but not every Chevy

car is a Volt.

Some alcoholic drinks are scotch whiskey. So every scotch whiskey is an

alcoholic drink, but not every alcoholic drink is scotch whiskey.

Some small dogs are puppies. So every canine puppy is a small dog, but not

every small dog is a puppy.

Some readable publications are newspapers. Every newspaper is a readable

publication, but not every readable publication is a newspaper.

Some fingers are thumbs. So every thumb is a finger, but not every finger is

a thumb.

Some military officers with additional qualifications and accomplishments are Generals.

Every General is a military officer, but not every military officer is a General.