I need the statements and reasons for this: ABCD is a parallelogram and we must prove AB=CD and BC=DA. If a quadrilateral is a parallelogram, then its opposite sides are congruent.

Alright, let me juggle some statements and reasons for you:

Statement: ABCD is a parallelogram
Reason: Given

Statement: ABCD is a quadrilateral
Reason: Definition of parallelogram

Statement: Opposite sides of a quadrilateral are congruent in a parallelogram
Reason: Property of parallelograms

Statement: AB and CD are opposite sides of ABCD
Reason: Definition of opposite sides

Statement: Therefore, AB = CD
Reason: Applying the property of opposite sides to AB and CD

Statement: BC and DA are opposite sides of ABCD
Reason: Definition of opposite sides

Statement: Therefore, BC = DA
Reason: Applying the property of opposite sides to BC and DA

Hope that adds a touch of laughter while proving the congruence!

Statement: ABCD is a parallelogram.

Reason: Given.

Statement: ABCD is a quadrilateral.
Reason: Definition of a quadrilateral.

Statement: Opposite sides of a parallelogram are congruent.
Reason: Property of parallelograms.

Statement: AB and CD are opposite sides of parallelogram ABCD.
Reason: Definition of a parallelogram.

Statement: Therefore, AB and CD are congruent.
Reason: Applying the property of opposite sides of a parallelogram.

Statement: BC and DA are opposite sides of parallelogram ABCD.
Reason: Definition of a parallelogram.

Statement: Therefore, BC and DA are congruent.
Reason: Applying the property of opposite sides of a parallelogram.

Therefore, AB=CD and BC=DA, as required.

To prove that AB = CD and BC = DA in a parallelogram ABCD, we can use the fact that in a parallelogram, the opposite sides are congruent. Here are the statements and reasons for the proof:

Statements:
1. ABCD is a parallelogram (Given)
2. AB || CD (Definition of a parallelogram)
3. BC || DA (Definition of a parallelogram)

Reasons:
1. Given
2. In a parallelogram, opposite sides are parallel.
3. In a parallelogram, opposite sides are parallel.

Now, to prove AB = CD, we can use the fact that AB || CD:
4. AB || CD (Given)
5. AB = CD (Corresponding Angles Postulate - If two parallel lines are cut by a transversal, then corresponding angles are congruent)

To prove BC = DA, we can use the fact that BC || DA:
6. BC || DA (Given)
7. BC = DA (Corresponding Angles Postulate - If two parallel lines are cut by a transversal, then corresponding angles are congruent)

Therefore, we have proven AB = CD and BC = DA in parallelogram ABCD using the fact that in a parallelogram, the opposite sides are congruent.

ummm, that's the definition of a parallelogram.