kě / zhǎn / qū / miàn / kě / yǐ / zhǎn / kāi / chéng / yí / gè / píng / miàn / ér / bú / biàn / xíng

可展曲面可以展开成一个平面而不变形。

A developable surface can be unfolded into a plane without deforming.