radius = 18/2 = 9 cm
Chat with our AI personalities
18cm is about 7 inches
The general equation for the area of a circle is π*r2, where r is the radius of the circle, and π is pi, which is approximately 3.14159. The diameter of a circle is how far it is from one side of the circle to the other, and the radius is how far it is the from edge to the center, thus the radius is half the diameter. Therefore the area is π*(92) ~ 254.47
A = 254.47 cm2
Radius = Diameter/2 Diameter = 2* Radius
A radius is one half of a diameter so divide by two to get from a diameter to a radius. Or you can multiply the radius by 2 to get to the diameter.