Vertical angles are congruent (equal in measure) and they have the same vertex point.
The image would coincide with the pre-image during the rotation. Therefore, the octagon would coincide a total of 8 times as it rotates 360 degrees about its center.
Use CamScanner, a free app, to take a picture of your word problem. Try uploading the question again? This is the tactic I use for pictures on Brainly
herp derp herp derp herp derp