Final answer:
The solid with 6 rectangular faces, 2 equal non-rectangular bases, and 18 edges is a hexagonal prism.
Step-by-step explanation:
The three-dimensional solid described as having 6 rectangular faces, 2 equal bases that are not rectangles, and 18 edges is a hexagonal prism. A hexagonal prism consists of two hexagonal bases and six rectangular sides that connect the corresponding sides of the two bases. Each base has 6 sides, and adding the 6 sides of the rectangles makes for a total of 18 edges. This is consistent with the prism's geometric properties. The shape is different from an octahedron or an icosahedron which consists of triangular faces and does not have rectangular faces as specified in the question.