Answer:
20-gon
Step-by-step explanation:
First we start with the formula to find what the sum of angles will be if we know the number of sides.
S=(n-2)*180 where S is the sum of angles and n is the number of sides.
Normally you'd plug in n to find S, but you can do the opposite too.
3240=(n-2)*180
Let me know if you need help working it from here.
It would still be 17.8, unless there are more numbers after the 8.
The answer is 84 because of process priority