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.
One acre is approximately 40% the size of a hectare. The history of the acre dates back hundreds and hundreds of years, deriving from the Old English word âÃ¦cerâ which meant an open field. The acre was said to be a measurement of the amount of land that one man and his ox could till in one single day. Our acreage calculator can be used with any of the following shapes of land: parallelogram, rectangle, rhombus, square, trapezoid, or triangle.