Are you saying the side is 6 inches? ie lenght of the base. i just dont think u have enough data there to work this out?
1 ft = 12 inches
therefore, 15 inches is more then 1 ft
396 out of 2800 shirts are defected.
396/2800 * 100 = 14.1% of the shirts were defected
Diameter- Is two times the radius. Circumference is the distance around the edge of the circle.
Radius- A line from the center of a circle to a point on the circle.
Hope this helped.