360 degrees=2pi radians
therefor set up a ratio and proportiopn
a.
360/2pi=40/x
times 2pix both sides
360x=80pi
divide both sides by 360
x=(2pi)/9 radians
b.
360/2pi=-570/x
times 2pix both sides
360x=-1140pi
divide boh sides by 360
x=-(19pi)/6 radians
a. (9pi)/2 radians
b. (-19pi)/6 radians