The surface area is made up of the end faces and rectangular ... The volume of the prism is 90 mm³. The area of the parallelogram is the base multiplied by the height. 9 × 4 = 36.

On a fresh surface of a cleaved single crystal such ... on a hexagonally symmetric pattern consisting of locally rubbed parallelograms (Fig. 1). The shape of the parallelogram was designed to ...