The meaning of the area is the measurement of a surface in this case a circle, which can be find by using the formula 
, where r is equal to the radius of the circle.
In this exercise is given that the diameter of a standard cardboard is 18 inches or a radius of 9 inches and it is asked to find its area. Therefore, to find the area of the circle you should substitute the value of the radius into the previous mention formula.
The area of the standard dartboard is 254.47 square inches or 254 square inches.
In this exercise is given that the diameter of a standard cardboard is 18 inches or a radius of 9 inches and it is asked to find its area. Therefore, to find the area of the circle you should substitute the value of the radius into the previous mention formula.
The area of the standard dartboard is 254.47 square inches or 254 square inches.