##R.= 6##, ##C. ~~ 38## and ##A. ~~ 113##.
First you need to find the radius, the key term to find the radius is ##diameter = 2*radius##; therefore the radius ##r## is ##12/2 = 6## inches.
To find the area of a circle, you need to use the formula ##A = pi*r^2##; therefore the area ##A## is ##pi*6^2 ~~ 113## square inches.
To find the circumference of a circle, you will use the formula ##C = 2*pi*r##; therefore the circumference ##C## is ##2*pi*6 ~~ 38## inches.
