Answer:
30
Step-by-step explanation:
30 dived by 5 is 6 then 6 times 5 is 30
A/d c/h e/f g/b :) I think
Unsure of what you mean by "reference number."
I do recognize that 11pi/9 is in quadrant III. I suspect that the so-called "reference number" is the acute angle between the end ray of 11pi/9 and pi, or, in more easily comparable numbers, between 9pi/9 and 11pi/9.
That difference is 2pi/9.
