useless triv 56: the phone book in what country is alphabetic ... by first name?

Questions

Mathematics : Name the number system which uses only the symbols 1 and 0.?

Mathematics : The angles inside a square total _______ degrees.?

Mathematics : The mathematical study of properties of lines, angels, etc., is ________.?

Mathematics : The space occupied by a body is called its ______.?

Mathematics : Two angles that total 180 degrees are called _______.?