Answer:
circular plate
Step-by-step explanation:
Rotational symmetry is attained on a figure if it is possible to achieve the same image of the figure after rotating it. For example , rotating a circular plate marked with numbers 1 to 6 through a 360° rotation, the number marked 1 with attain a position similar like that before rotation.
A straight angle is equal to 180 degrees. 180-80=100. 100-60=40. so y=40. vertical angles are congruent so x=40 degrees.
