Answer:

Step-by-step explanation:
Have a nice day
This might help it has tons of different problems for your subject.
https://www.wyzant.com/resources/lessons/math/algebra/calculators/proportion
A nonagon has 9 sides, so n = 9
S = sum of the interior angles
S = 180*(n-2)
S = 180*(9-2)
S = 180*7
S = 1260
Answer is choice B