The number of pizzas eaten at the class party is equal to one-forth the number of students, plus two more pizzas for the adult. if nine pizzas are eaten, how many students are there

a_n = a_1 + (n - 1)d

the first term is 6.

the common difference d = ?

when you find d, replace n with 7 and d with the common difference to find your answer.

answer is 270 degrees: -

to convert radians to degrees you multiply by 180/π

9π/ 6 * 180 / π

=   9 * 180 / 6

= 9 * 30

=   270 degrees   answer