Which geometric figure has diagonals that bisect each other?

A parallelogram is a geometric figure in which both pairs of opposite sides are equal in length and parallel. One key property of a parallelogram is that its diagonals bisect each other. This means that the point where the two diagonals intersect divides each diagonal into two equal lengths.

This property holds true regardless of the specific type of parallelogram, whether it's a rectangle, rhombus, or square. Therefore, when you draw the diagonals of a parallelogram, you will always find that they meet at a point that bisects each diagonal, resulting in two segments of equal length on each diagonal.

The other figures listed do not share this property. In a triangle, the diagonals do not exist in the same way they do in polygons with more sides, and any lines drawn between non-adjacent vertices do not bisect in the manner described. A circle has no diagonals since it is a round shape, and an octagon has diagonals, but they do not bisect each other in the same way that those in a parallelogram do. Therefore, the correct answer clearly highlights the unique property of the parallelogram's diagonals.