Math challenges! 1

1. Is 729 a cubed number? If so, what is the number you cube?

2.
a. Is 1,681 a square number?
b. Is 4,356 a square number?
c. Is 5,901 a square number?
d. Is 8,976 a square number?
e. For the numbers that ARE square. Find out what number you square.

3. Is 1830 a triangular number?