To solve this problem, we need to understand the properties of a parallelogram. Here’s a detailed step-by-step solution:
1. Understanding a Parallelogram:
A parallelogram is a type of quadrilateral. A quadrilateral is any shape with four sides. In a parallelogram, both pairs of opposite sides are parallel. This is the key characteristic that defines a parallelogram.
2. Properties of a Parallelogram:
- Parallel Sides: Both pairs of opposite sides are parallel.
- Equal Length of Opposite Sides: As a result of the parallel pairs, the opposite sides of a parallelogram are also equal in length.
- Equal Opposite Angles: The opposite angles are equal.
- Diagonals: The diagonals of a parallelogram bisect each other.
- Supplementary Consecutive Angles: The consecutive angles (angles next to each other) are supplementary, which means they add up to 180 degrees.
3. Evaluating the Answer Choices:
- Diagonals: This is not a property of the opposite sides but rather a property related to the diagonals within the parallelogram itself.
- Convex: This term describes the shape as a whole, not specifically the property of the sides.
- Supplementary: This term is related to angles within a parallelogram and not the sides.
- Congruent: This term means having the same size and shape. In the context of a parallelogram, it implies that the opposite sides are equal in length, which correctly describes a property of parallelograms.
4. Conclusion:
Given the properties and evaluating the choices, the correct term that correctly describes the nature of the opposite sides in a parallelogram is "congruent."
Therefore, if a quadrilateral is a parallelogram, then its opposite sides are congruent. The correct answer is:
4. Congruent.
