small bathrooms. i have kind of a similar fear, but I'm really only scared of small bathrooms, or monochromatic ones or ones with labels and directions as to what to do (like airplane or cruise ship bathrooms) I hate flying because of my fear, and always avoid airplane bathrooms.
A rectangular prism is solid 3-dimensional object which has six  faces that are rectangles. It has 12 edges and 8 vertices.
A triangular prism has five sides, six vertices and nine edges. A triangular pyramid, on the other hand, has four sides, four vertices and six edges. In case of a triangular prism, the area of cross section along the axis perpendicular to the base does not change.