Perhaps you mean The Forum, but it's more trapezoidal than rectangular.
The open central court inside of a house in ancient Rome was called an "atrium".
The ancient Romans called any large open area a campus. An example is the Campus Martius at Rome.
open the bonnet on your car, look for a large black plastic box, that is it. on diesels usually rectangular, petrols circular i believe,
Large open economy.
There will be a small rectangular button underneath your opening. Push it.
No, it is an open border.
1 rectangular face (the square base) and 4 triangular faces. Justin Dip(Math) Open
The center of ancient Rome was the Forum, the open plaza and marketplace around which the government buildings were located.
A central glass-roofed hall is commonly referred to as an atrium. It is a large open space within a building that is often surrounded by multiple levels and designed to allow natural light to illuminate the interior.
about 10ad
You cannot make a solid shape with 5 rectangular sides. You can make an open rectangular box, leaving off the last side. You can make a rectangular box (like a cube, but with possibly unequal sides) with 6 rectangles. You can make a rectangular pyramid with one rectangle and four triangles.
It depends on how many sides are part of the "opening".