Which of the following statements are true about all parallelograms? I. Opposite sides are congruent. II. Diagonals are perpendicular. III. Diagonals bisect each other. N. Opposite angles are congruent. I, III, IV only II, III only I, II, IV only I, III only

In the world of parallelograms, the statements that ring true universally are that opposite sides are indeed congruent and diagonals bisect each other. This means regardless of the types of parallelograms you're dealing with, whether they're rectangles, rhombuses, or squares, this rule stands firm. As for perpendicular diagonals, that trait is unique to specific varieties, like rhombuses! For practical understanding, you can visualize how these properties come alive. If you grab a ruler and paper and sketch a parallelogram, then measure opposite sides, you'll find they are equal! If you draw the diagonals, they'll meet at their midpoints, demonstrating that they bisect each other. This hands-on experiment will help solidify those concepts in your mind.