Find the angle complementary to ; pie over 18

Question

Choices are ;

 

5 pie over 9

 

17 pie over 18

 

4 pie over 9

 

9 pie over 18

 

Answer 1

Complementary angles add up to pi/2

 

The complementary angle of pi/18 would be:

 

Pi/2 - pi/18 = 8pi/18 = 4pi/9