What is the contrapositive of the following statement?
If ∆ABC is equilateral, then it is isosceles.
If ∆ABC is not isosceles, then it is not equilateral.
If ∆ABC is isosceles, then it is equilateral.
If ∆ABC is equilateral, then it is isosceles.
If ∆ABC is not equilateral, then it is not isosceles.