What is a 3D rectangular object called?

A three-dimensional rectangular object is called a "cuboid," which means "similar to a cube" or "resembling a cube." It is also referred to as a "rectangular parallelepiped."

A cuboid contains six plane surfaces, with all of its vertices forming 90-degree angles. Two of a cuboid's properties are volume and surface area. The formula for calculating the volume is V = lwh, where "V" denotes the volume, "l" indicates the length, "w" represents the width and "h" is the cuboid's height. The formula for the surface area is A = 2wl + 2lh + 2hw, where "A" is the surface area. A cuboid can be classified as a "prism" because it has a uniform cross-section along its length.