1. The number of equilateral triangles that can be formed by three vertices of a cube is
(A) 4
(B) 8
(C) 12
(D) 24
(B)
I. Multiple Choice Question
1.【Analysis and Solution】In a cube, at a common vertex of three mutually perpendicular faces, there is a pair of diagonals that together form a unique equilateral triangle. This establishes a one-to-one correspondence between the equilateral triangle and the vertex. Since a cube has 8 vertices, there are exactly 8 equilateral triangles.