unit circle
cos 0 = 1
sin 0 = 0
cos 30 = √3/2
sin 30 = 1/2
cos 45 = √2/2
sin 45 = √2/2
cos 60 = ½
sin 60 = √3/2
cos 90 = 0
sin 90 = 1
cos 120 = -1/2
sin 120 = √3/2
cos 135 = -√2/2
sin 135 = √2/2
cos 150 = -√3/2
sin 150 = 1/2
cos 180 = -1
sin 180 = 0
cos 210 = -√3/2
sin 210 = -1/2
cos 225 = -√2/2
sin 225 = -√2/2
cos 240 = -1/2
sin 240 = -√3/2
cos 270 = 0
sin 270 = -1
cos 300 = ½ sin 300 = -√3/2
cos 315 = √2/2
sin 315 = -√2/2
cos 330 = √3/2
sin 330 = -1/2.