Calculate the sum of the measures of the interior angles of a 9 -gon.

13 x 5 = 65
65 + 7 = 72

Explanation:

First set up the equation with ‘x’ being the unknown number. Then set up an inequality where the actions done to x equal 13.

(x-7)/5=13

Now solve for x

First multiple both sides by 5 That gives us

X-7=65

Now add seven to both sides to isolate and solve for x

X=72