Prove that quadrilateral ABCD is a parallelogram. How do you know that the figure is a parallelogram? (1 point) Responses Adjacent sides of the figure are parallel. Adjacent sides of the figure are parallel. Opposite sides of the figure are congruent. Opposite sides of the figure are congruent. Adjacent angles of the figure are congruent. Adjacent angles of the figure are congruent. Adjacent sides of the figure are congruent. Adjacent sides of the figure are congruent. Skip to navigation

To prove that quadrilateral ABCD is a parallelogram, we can use one of several properties that confirm a shape is a parallelogram. Here’s a quick overview of some of these properties:

1. **Opposite sides are parallel**: If both pairs of opposite sides of a quadrilateral are parallel, then the quadrilateral is a parallelogram.

2. **Opposite sides are congruent**: If both pairs of opposite sides are congruent, the quadrilateral is a parallelogram.

3. **Opposite angles are congruent**: If both pairs of opposite angles are congruent, the quadrilateral is a parallelogram.

4. **Diagonals bisect each other**: If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram.

5. **One pair of opposite sides is both parallel and congruent**: If one pair of opposite sides of a quadrilateral are both parallel and congruent, the quadrilateral is a parallelogram.

Given your options, here’s how we can confirm the proof based on the appropriate property:

- If **opposite sides of the figure are congruent**, then quadrilateral ABCD is indeed a parallelogram.

So, in response to how you know that the figure is a parallelogram, the correct response would be:

**Opposite sides of the figure are congruent.**