The radius of circle a is 2 cm, and the diameter of circle B is 4 cm. Are the perimeter of the two circles equal?

The radius of circle a is 2 cm, and the diameter of circle B is 4 cm. Are the perimeter of the two circles equal?

Equal, because the diameter of the circle is twice the radius, so the two circles are the same, that is, the perimeter is equal, the area is equal