I pretty sure the answer is c
3x is the least common denominators because you need to be able to make sure all other denominators can go multiple into it. Since the rest are just x, the largest number of 3x would be the denominator you want.
To find the sum of the interior angles of a nonagon, divide it up into triangles... There are seven triangles... Because the sum of the angles of each triangle is 180 degrees... We get
7 * 180 = 1260°
So, the sum of the interior angles of a nonagon is 1260 degrees.
