Reference angles

Question

Draw each angle in standard position. Determine the reference angle in each case.

 

a) 240 degrees

 

b.) -2pie/3

Answer 1

240 -180 = 60 = pi/3 = reference angle

-2pi/3 + pi = (3-2)pi/3 = pi/3 = 60 degrees = reference angle

the reference angle is the acute angle (less than 90 degrees), between the terminal angle and the x axis

the reference angle is always >0