One acre is 43,560 square feet and has various dimensions. According to Wikipedia, well-known dimensions of an acre are 66 feet x 660 feet or 208.71 feet × 208.71 feet. Common dimensions for U.S. residents are 88 yards by 55 yards, slightly more than 75% of an American football field.
An acre is a measurement of area and is measured in square feet. Therefore, the dimensions of an acre can vary. Wikipedia adds that an acre has no prescribed shape and the dimensions can form different shapes which include rectangles, circles, squares and triangles. However, the area of the acre must equal 43,560 square feet.