Perimeter of a 3D shape

Answer 1

A "perimeter" is a 2D measurement and cannot be applied to a 3D object. However, sometimes the area around a building or piece of property to be protected is known as a perimeter. In that case, measure the sides of the facet of the object facing the ground, add them up and you have a perimeter.

"Surface area" would be the closest thing to a perimeter, purely speaking. Measure the area of one facet of an regular 3D object (such as a cube), multiply that number by the number of facets, and you get the surface area.