Centimeter
A centimetre should suffice.
The head or the point of the pin? I would measure the head in millimeters and the point of the pin in micrometers.
METERS!!!The unit of measurement you would use to measure the width of your classroom is meters.
ruler
First: 36 cm2 cannot be a width. Width is a linear measure - a measure of distance - which would be measured in cm and not cm2. In any case, having just the width is not sufficient information for answering the question.
meters
A centimetre should suffice.
It depends on what you are measuring the width of. Different units and different tools would be appropriate for a hair, a car or a galaxy.
The head or the point of the pin? I would measure the head in millimeters and the point of the pin in micrometers.
Depending on your countries standard unit of measurement but either feet or meters would be the answer.
Meters or feet are commonly used to measure the width of a house.
METERS!!!The unit of measurement you would use to measure the width of your classroom is meters.
To measure a sharpener in the metric system, you would typically use centimeters (cm) for its length, width, and height. If you need to measure smaller dimensions, millimeters (mm) might be more appropriate. For weight, grams (g) would be used.
Centimetre.
Parsecs
The metric unit of the meter would be the appropriate measure of the area of classroom. Calculating area involves multiplying the length (in meters) of the classroom's length and width. Area of the classroom would be in square (^2) meters.
The width of a highway would be best measured in meters. The length would be measured in kilometers.