Write the two statements that form each biconditional. 6. Two lines are perpendicular if and only if they intersect to form four
right angles.
7. A whole number is divisible by 3 if and only if the sum of the digits of the whole number is divisible by 3.
8. A whole number is an odd number if and only if it is not divisible by 2.
9. A person lives in Alaska if and only if the person lives in the northernmost state in the United States.