The student has a fairly good concept of one-half. However, she does not consider h (shown below) to show one-half. This parallelogram is partitioned with a vertical line that is not parallel to the sides of the figure. This causes her problems. She is unable to see that the left side could be rotated and placed directly on the unshaded part. Perhaps her concept of rotation is not well developed.
Her response to m (shown below) is interesting. At first, she rejects the figure as having one-half shaded. However, when I call her attention to it, she provides an insightful explanation involving a translation of the unshaded triangle on the right over to the left to form an equilateral triangle congruent to the shaded region.
— Grayson Wheatley