use a calculator with an inverse trig function
or go on line to desmos which has an on line calculator with an inverse sine function
sinx = 1/4
x = 14.478 degrees, approximately
or 180-14.478 = 165.522 degrees
or 14.478 + 360n where n = any integer
or 165.522 + 360n where n = any integer
or x=14.478 times pi/180 = 14.478pi/180 = about 0.08pi radians = about 0.2527 radians + 2npi radians where n= any integer
or 165.522 times pi/180 = 0.9196pi radians = 2.889 radians + 2npi radians where n= any integer
sinx=1/4 has an angle in the 1st or 2nd quadrant, where x could be an infinite number of different values, positive or negative