Well, darling, the area of a circle is calculated using the formula A = πr^2, where r is the radius. So, plugging in 18 cm for the radius, we get A = π(18)^2 = 324π cm². So, the area of a circle with a radius of 18 cm is 324π square centimeters. Voilà!
Chat with our AI personalities
1,017.9 m2
i believe that it is 18 if the radius is 9 edit: wrong, area = pi*radius^2 so it's 3.1415926535*81=254.469
First we have to find the radius: 2*pi*radius = 18*pi Divide both sides by 2*pi to find the radius: radius = 9 inches Area of a circle = pi*radius2 Area = pi*92 = 81pi or 254.4690049 square inches
The radius of a circle is always half of the diameter. Therefore, if the diameter of a circle is 36 units, the radius would be half of 36, which is 18 units. The formula for finding the radius from the diameter is radius = diameter / 2. So, in this case, the radius would be 18 units.
To find area of a circle, the formula is πr2 where π is pi. Half of the diameter is the radius (r) so you divide 18 by 2 to get the radius (9). then, you square it (multiply it by itself) giving you 81. You then multiply this by pi to get the area. The exact answer is 81π, with a good approximation of: 254.46900494077325231547411404563973361997072134938357149897