radius = 20/(2*pi) = 3.183098862 inches
r = 3.18 inches.
The answer will depend on what is 20 inches: the radius or diameter or something else.
If the radius of a circle is 8.5 inches the circumference is: 53.4 inches
If the circumference of a circle is 24 inches the radius is: 3.82 inches.
If the circumference is 20 the radius is 3.18
A circle with a radius of 72 inches has a circumference of 452.39 inches.
The circumference of a circle with a radius of 4.246 inches is about 26.68 inches.
The circumference of a circle with a radius of 10 inches is about 62.83 inches.
A circle with a radius of 9 inches has a circumference of 56.55 inches.
A circle with a radius of six inches has a circumference of 37.7 inches.
The radius of a circle with a circumference 36 inches is: 5.73 inches.