ANSWER:
1. A, B, C, D
2. ABC, ABD, ACD, BCD
3. AB, AD, CD, BC, BD, AC
Explanation:
A polyhedron is a solid body bounded by polygonal plane faces.
Vertices are the extreme points of the edges. At each vertex there are three or more faces.
Faces are the polygons that make up its surface.
Edges are segments, they are the sides of the faces. Each edge is a border of two faces.
Therefore:
1.
Vertices
A, B, C, D
2.
Faces
ABC, ABD, ACD, BCD
3.
Edges
AB, AD, CD, BC, BD, AC