The number is not a perfect square, if it can not be expressed as square of a number.
So an example of number that is not a perfect square is 8.
The ordered pair is the position of a point on the coordinate plane. It represent the x-coordinate and y-coordinate.
An example of an ordered pair is (2,4).
A trinomial is an expression which consist of three non-zero terms.
An example of trinomial is, 2x + 3y +4z.