Final answer:
A parallelogram is a four-sided figure with opposite sides that are parallel and equal. Defining properties include parallel and equal opposite sides and angles, supplementary consecutive angles, and bisecting diagonals. The parallelogram rule is related to vector operations in physics.
Step-by-step explanation:
A parallelogram is a four-sided polygon with opposite sides that are both parallel and equal in length. Several important properties define a parallelogram:
- Opposite sides are parallel (AB ∥ DC and AD ∥ BC).
- Opposite sides are equal in length (AB = DC and AD = BC).
- Opposite angles are equal (\angle A = \angle C and \angle B = \angle D).
- Consecutive angles are supplementary (sum to 180 degrees).
- The diagonals bisect each other.
The parallelogram rule referenced in the question likely pertains to the method used in vector addition or subtraction, where vectors are represented as sides of a parallelogram to find the resultant or difference vector.