A ≈ 28.27cm2
The circumference of a circle with a diameter of 6cm is about 18.85cm
Area of a circle = (pi) R2 = (pi) x (1/2 of the diameter)2 = 9 pi = 28.27 cm2 (rounded)
The exact area = pi*32 or 9*pi square cm
12 cm.
6cm
The radius of the circle is half the diameter of the circle. 30mm radius would mean 60mm diameter or 6cm.
12 cm
The diameter of circle A is 12cm so its radius must be 6cm.
6/2 = a radius of 3 cm
The circumference of a circle = 2*pi*radius or diameter*pi
Since the diameter is always twice the length of the radius, the length of the radius is 6cm.