Six Sigma is a set of techniques and tools for process improvement. It was introduced by engineer Bill Smith while working at Motorola in 1986. Jack Welch made it central to his business strategy at General Electric in 1995. Today, it is used in many industrial sectors.
One acre equals 0.0015625 square miles, 4,840 square yards, 43,560 square feet or about 4,047 square metres (0.405 hectares) (see below). While all modern variants of the acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends on which yard it is based.
Originally, an acre was a selion of land one furlong long and one chain wide. However, an acre is a measure of area, and has no particular width, length or shape. The acre is often used to express areas of land. In the metric system, the hectare is commonly used for the same purpose.An acre is approximately 40% of a hectare. One acre is 90.75 yards of a 53.33-yard-wide American football field.riginally, an acre was a selion of land one furlong long and one chain wide. However, an acre is a measure of area, and has no particular width, length or shape. The acre is often used to express areas of land. In the metric system, the hectare is commonly used for the same purpose.