Question

The sine of the complimentary angle of 28° a. -0.86 c. -0.74 b. 0.88 d. 0.76

Answer 1

Step One
Find the complimentary angle of 28o Compliments add to 90o.

28 + c = 90
c = 90 - 28  
c = 62o

Step two
Find the sin of 62o

sin(62) = 0.8829

So the answer is B

Another way to do it is to take the cos of 28
Cos(28) = 0.8829 which is still B.