Characteristics of Parallelograms:

• Opposite sides are parallel and the same length.
• Opposite angles are the same.
• The diagonals cross each other in the middle.
• The total of all the inside angles adds up to 360 degrees.

Characteristics of Rectangles:

• All angles are right angles (90 degrees).
• Opposite sides are equal and parallel.
• The diagonals are the same length and cross each other in the middle.
• The total of all the inside angles adds up to 360 degrees.

Main Comparison:

• Every rectangle is a parallelogram, but not every parallelogram is a rectangle because of the angle differences.