surface area       
noun [ C usually singular ]  mathematics specialized uk/ˈsɜː.fɪs ˌeə.ri.ə/ us/ˈsɝː.fɪs ˌer.i.ə/
 (物体的)表面积
the area of a surface or of all of the outer surfaces of something
  the surface area of a cube 一个立方体的表面积 
 See also: area