In basketball, the three-point line is at differing lengths depending on the age and level of competition. In the National Basketball Association, the three-point line is 22 feet when measuring from the center of the rim to the sides. The top of the arc is 23 feet 9 inches.
On a men's and women's collegiate court, the three-point arc measures at 20 feet 9 inches from the center of the rim. On high school courts, the arc is further shortened to 19 feet 9 inches from the center of the rim.
The three-point line was first used in 1961 in the American Basketball Association, but the current NBA didn't add the three-point line until 1979.