If the diameter of a circle is 18 inches then its radius is 18/2 = 9 inches
Diameter = twice the radius = 2 x 18 = 36 inches.
A circle with a radius of 9 inches has a circumference of 56.55 inches and a diameter of 18 inches.
A circle with a radius of 18 inches has a circumference of 113.097 inches.
A circle with a radius (d/2) of 18 inches has a circumference of 113.1 inches.
The diameter of a circle is twice the radius. A circle with a radius of 9 would have a diameter of 18. (9*2=18).
The radius is 18 inches (r = d/2).
The radius is 9 inches because area of circle is pi*9 squared = 81pi square inches and the diameter is twice the radius which is 2*9 = 18 inches
All depends what you mean by 18 inches, is that the circumference, the diameter or the radius
Radius is half the diameter. 18 is the answer.
36 inches. The radius is the distance from the centre to the outside or circumference and trhe diameter is the distance across passing through the centre. Therfore the diameter is twice the distance of the radius.