Answer:
1. There exists at least one square that is not a rectangle.
2. Every segment has a midpoint.
Explanation:
1.The given statement is: "All squares are rectangles". We have to find the negation of the statement. The statement that gives the negative meaning of the given statement is called the negation of the given statement. So the negation of the given statement is, "There exists at least one square that is not a rectangle".
2.Every segment has a midpoint.