Answer by
mathdanmom (16)

If the circle measures 12 feet across, through the center, then 12 feet is the diameter. In that case, the radius is half as long, which is 6 feet. However, if the 12-foot measurement is the distance around the circle instead, then 12 feet is the circumference. The radius would be 12/(2pi), or approximately 1.9 feet.