What is the sin 250 degree when expressed as a positive acut
     What is the sin 250 degree when expressed as a positive acute angle?  A) sin 70 degree  B) sin 20 degree  C) -sin 70 degree  D) -sin 20 degree 
  
  Solution
The coterminal angle of 250 degrees is, 250 - 180 = 70 degrees.
Also, 250 degrees is preset in 3rd quadrant where Sin is negative.
So sin 250 = - sin 70
So option C is correct.

