This is in continuation of my earlier post here.
On pg.#8-9, question #8 concerns finding a quantitative measure for distance function that can help to find closeness/similarity between two rectangles. Also, the attributes of concern are : length, height, aspect ratio, length
of the diagonal, angle between the diagonals, etc.
The part (c) concerns showing which of the two pairs among the $3$ possible for the $3$ points ($(3,2), (4,3), (5,4)$) representing rectangles are most similar or closer in shape.
To make two similar rectangle that are similar to share the same metric, we might like to consider $\max\left( \frac{y}{x}, \frac{x}{y}\right).$
In that case, rectangle represented as $(1,2)$ and rectangle represented as $(2,1)$ are considered identical. Also the metric doesn't take size into consideration.