Figure 5.
(a) an object composed of four smaller sub-objects; (b) the same configuration at smaller scale. The depth difference between the super-objects (a) and (b) should equal the depth difference between sub-objects such as (a)1 and (b)1.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.