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.
Observers were required to report whether the circle in the first display was larger or smaller than that circle in the second display having the same azimuth. The various sizes of the other circles were to be ignored.
