Schools in the UK have largely converted to the metric system. While the old Imperial system is prominent in some areas of engineering that, too has mostly changed. Few, if any, school leavers nowadays could readily convert Imperial to Metric, except with the most basic units.
English.
foot is the most precise way to measure any unit
Centimeters.
Foot
Oh, dude, like, a unit of measure smaller than a foot is an inch. It's like, you know, one of those things that's like, smaller than a foot but still kinda useful for measuring stuff. So yeah, an inch is the answer.
Though there is no exact Imperial equivalent to the metre the SI units of measurement are replacing the Imperial units as they are more convenient and self consistent.
English.
foot is the most precise way to measure any unit
A square unit is a measure of area, a foot is a linear unit. There are no area units in any linear measure.
Vertical Foot
Square Foot
The ISO length unit to use would be the cementer.
foot
meter
Centimeters.
A foot.
The pound is the basic unit.