How do you know the quotient of 639÷6 is greater than 100 before you actually divide

You make and sell triangular flags. each flag has a base of  3.53.5  feet and a height of  2.52.5  feet. fabric for the flags costs  $0.40$0.40  per square foot. what is the cost to make one flag?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

Alicia puts $400 in a bank account. each year the account earns 5% simple interest. how much money will be in her bank account in six months?