Question

If a figure has four sides, it is a quadrilateral.

What is the contrapositive of this statement?

Answer 1

If a figure is a quadrilateral, it does not have four sides.
If a figure does not have four sides, it is a quadrilateral.
If a figure is not a quadrilateral, it does not have four sides.
If a figure has four sides, it is not a quadrilateral.

Answer 2

If A then B

Contrapositive:

If not A then not B

Think of it this way:
If A is true then B must also be true. So if A isn't true, then B isn't true either.