What are the similarities between standard units and non-standard units?

Standard units of measurement are units of measurement that are typically used within each measurement system, such as inches, feet, ounces, pounds, kilograms, or cups. ... Nonstandard units of measurement are units of measurement that aren't typically used, such as a pencil, an arm, a toothpick, or a shoe.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y