What is the difference between a round number and a square number? [closed]

What is the difference between a round number and a square number? I know that a round number can be circular in shape, and a square number has a shape similar to that of a cereal box (if the box is not rectangular). But I'm not sure if rectangular or triangular numbers even exist.

This is, of course, a math terminology question, so the answer involves formal definitions from that field.

Round number generally means a number approximated or estimated such that it ends with a series of 0 digits; not an exact measurement. For example, 597 would be rounded to 600 for convenience and brevity in speaking. See Wikipedia: Round number.

Square number means the result of the squaring operation, usually starting from some integer; this corresponds to the area of a square with sides of some integer unit. For example, 1, 4, 9, and 16 are square numbers, because 1² = 1, 2² = 4, 3² = 9, and 4² = 16. See Square number.

Triangular number is the sum of the first several positive integers to some point; this corresponds to the number of things in a triangular arrangement. For example, 10 is a triangular number, because 1 + 2 + 3 + 4 = 10. See Triangular number.

Rectangular number is the product of two sequential integers, also called "pronic" numbers. For example, 5 × 6 = 30 and 11 × 12 = 132 are rectangular numbers. (Alternatively, some use "rectangular" to refer to composite numbers.) See Pronic number.

It may be of interest that the Nth rectangular number is always twice the Nth triangular number, and N more than the Nth square number (noted in prior link).

For a large list of other named types of numbers, see here: Types of Math Numbers.