<span>To do these you will be adding or subtracting 2pi (or integer multiples of .
Since the given angles are in fraction form, it will help to have 2pi in fraction form, 2pi=10/5=6pi/3=4pi/2=18pi/9 NOTE: this>(/) stands for over like 1 over 2 EX. 1/2
too, so the addition/subtraction is easier.
Hint: When deciding if you have a number between 0 and 2pi, compare it to the fraction version of 2pi that you've been adding/subtracting.
For 17pi/5...
First we can see that 17pi/5 is more than 10pi/5 (aka 2pi). So we need to start subtracting: 17pi/5 - 10pi/5 = 7pi/5
Now we have a number between 0 and 10pi/5. So 7pi/5 is the co-terminal angle between 0 and 2pi.
I'll leave the others for you to do. Just remember that you might have to add or subtract multiple times before you get a number between 0 and 2pi.
P.S don't add or subtract at all if the number starts out between 0 and 2pi.</span>
The square root of 16 is 4
3s+28=85, take away 28 from both sides of the equals to give you 3s=57, divide by 3 on both side to give you s=19.
You can eliminate 81 because we know 
The dot is on approximately 9.32 (my estimate) so I would square that number:
(9.32)² = 86.8624 so if you round this you get 87
