9. what is the formula to find the sum of the interior angles for any polygon?
what does n stand for in the formula?
how many sides are in an octagon?
find the measure of one interior angle of a regular octagon

At the county fair, animals are judged for the quality of their breeding and health. the animal pens are arranged in an array, with one animal in each pen. a barn can hold at most 10 rows of pens and at most 6 pens in each row, with room for people to walk around them. what different ways can the planners of the county fair arrange the pens for the horses and cows in the same barn?