Figure 4.
(a) An example curved surface and a meter stick; (b) a view of the indoor environment in Figure 3(i) looking towards the right, showing the top, right, and bottom walls.
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.