Question 1080058
Refer to the Unit Circle to get the reference values for cosine of each of your angles.  From those, use simple computation for {{{r=8*cos(theta)}}}, or use a calculator if you want decimalized values.


You should be able to refer to {{{system(cos(0)=1, cos(45)=sqrt(2)/2, cos(90)=0, cos(135)=-sqrt(2)/2)}}}, etc...