Centimetres.
Any sort of scale can be used to measure weight, which can then be used to help calculate mass. There do exist 'massometers', but those are usually less common except in laboratory environments.
one page of a phonebook is measured in mm. unit thickness of a phone book is cm
It can be measured in any energy unit you like, just as you can measure the length of a book in any length unit. Chemists most often use kilojoules.
you measure the thickness of a book in inches.
155 mm
Inches or centimeters
I think I saw that you tried to include that your units were in inches. this is not a metric unit to start. convert inches to centimetres. then multiply the length by the width to get your answer in cm^2, a metric unit
centimeter
A ruler
the metric system
Probably centimeters.
I would measure it with a ruler.
Any sort of scale can be used to measure weight, which can then be used to help calculate mass. There do exist 'massometers', but those are usually less common except in laboratory environments.
I suggest you use a ruler.
Inches or centimetres are fine for a book's dimensions. Measure the width, height and depth to determine the volume. If you are talking about the length of the book's narrative, word count is probably the most accurate.
You would typically use inches to measure a paperback book. You can measure the length, width, and thickness of the book in inches to determine its size.
To find the area of a book cover in metric units, the most appropriate unit to use would be centimeters. The formula for finding the area of a book cover would be: length x width.