Methyl cation, anion, and radical. Methyl cation. The methylium cation (CH3+) exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the CH3+ cation, and this simplification is used pervasively in organic chemistry.
The square foot (plural square feet; abbreviated ft 2 or sq ft) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States and partially in Canada, United Kingdom, Hong Kong, Bangladesh, India and Pakistan. It is defined as the area of a square with sides of 1 foot.
1 square foot = approximately 0.000022959 acres. 1 acre = 43,560 square feet. To calculate the area of a room in square feet, measure the length and width of the room in feet, then multiply these figures together to give an area in ftÂ².For example, a room measuring 12 ft x 15 ft would be described as having an area of 180 ftÂ² (12 x 15 = 180). 1 square yard (Sq Yd) = 9 ftÂ². 2  One yard is three feet, so a square yard can be imagined as a square with sides of three feet, or a square block comprising nine individual squares with sides one foot in length.