sat2数学求解a plane cuts through a cube in such a way that the p

sat2数学求解
a plane cuts through a cube in such a way that the plane passes through three of the cube's vertices, no two of which lie on the same edge. if the edge of the cube has a length of 1, what is the surface area of the smaller fragment of the cube?
a, 2.4
b 2.7
c 3.1
d 3.7
e 4.3
求过程