Better to use 180 because is it **less** than 230. Basically, you need an angle between 0 and 90 degrees. Using 230- 180= 50 you would argue that sin(50)= 0.7660 and cos(50)= 0.6428 but since 230 degrees is in the third quadrant, where both sine and cosine are negative, sin(230)= -0.7660 and cos(230)= -0.6428. On the other hand, 230- 270= -40. That is NOT positive so not between 0 and 90 degrees. It **could** be used if you use sin(-40)= -sin(40) and cos(-40)= cos(40).