<em>flat surfaces on a rectangular prism are called faces..
<u>reason:
</u>it is so because those surfaces are of polyhedron shape means that their spherical surfaces are in front and they have a general outward appearance .. Face is a Latin word( facies) meaning
<u>in front...</u>polyhedron shape is like:
</em>
You just have to add. Ex AC you would add them and see if it's the same if you add DF