Question

Rewrite the following biconditional as two conditionals:

A quadrilateral is a parallelogram if and only if it has two pairs of opposite sides that are parallel.

Answer 1

1. If it has two pairs of opposite sides that are parallel, then a quadrilateral is a parallelogram.
2. If quadrilateral is a parallelogram, then it has two pairs of opposite sides that are parallel.

Explanation:

One of the conditions has the condition and the conclusion written in one order; the other has them written in the opposite order.

• If it has two pairs of opposite sides that are parallel, then a quadrilateral is a parallelogram.
• If quadrilateral is a parallelogram, then it has two pairs of opposite sides that are parallel.