How to Calculate Square Constellation _ How to Calculate Square

How is the area (square degree) of the constellation calculated?

Y398297508 is wrong. It regards the celestial sphere as cubic flatness: the total is not 360*360 square degrees, but 360*360/π square degrees, which is about 4 1252.95 square degrees. It can also be said that it is (2π * 2π)/π = 4π radian. So the area of the sphere is calculated by 4 π r 2. Not direct r 2. (See Baidu Encyclopedia-Fangdu is OK! ! )