Olek has come up with a proof showing that an octagon has an interior angles sum of 1440. Using a straightedge, draw a convex octagon. Draw a point inside the octagon. . Connect the point to each vertex on the octagon. . There are 8 triangles in the diagram, so the sum of the interior angles in all of the triangles is 8 x 180 = 1440 . The interior angles sum for an octagon is 1440. a. Compare Olek's conclusion with the result obtained from applying the interior angles sum formula