ATLANTA — The unemployment rate in the metro Gainesville area fell to 7.2 percent in March, down three-tenths of a percentage point from a revised 7.5 percent in February, Georgia Department of Labor announced today. The jobless rate in metro Gainesville, which includes all of Hall County, was 8.5 percent in March 2011. The rate dropped because there were fewer layoffs in construction, manufacturing, trade and administrative and support services, the Labor Department said.