What do you call a four-sided polygon with four right angles and the opposite sides equal?

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

In an improper fraction, is the numerator equal to, less than, or greater than the denominator

Jane has 5 nickels.john has 3 dimes.jane says she has a greater amount of money.with the information given,is she correct?