7 pi = 21.991 (rounded)
Circumference = pi*diameter = 21.99 inches, approx.
A circle 14 inches in diameter has a radius of 7 inches, and a circle having a radius of 7 inches has a diameter of 14 inches.
A circle with a diameter of 7 inches has an area of 38.48 square inches.
circumference of a circle = pie times the diameter = 22/7 x diameter = 22/7 x 7 inches = 22 inches
The circumference of a circle if the diameter is 7 inches and Pi is 3.14 is: about 21.98 inches.
7/pi = diameter
2*pi*radius of the circle or diameter*pi where pi = 3.1416 or 22/7 and is usually rounded to 3.14.
It depends on what you mean by a "7-inch circle". If, as is normally the case, it is a circle with a 7-inch diameter, then you've got your answer in the question. If, unusually, you mean a circle with a 7-inch radius, then the diameter is twice that - 14 inches. If, even more unusually, you mean a circle with a circumference of 7 inches, then the diameter is 7/pi = 2.228 inches.
Its diameter: 2*3.5 = 7 inches
Circumference = 7*pi inches
14 inches.
7 inches, radius+1in=diameter. Always.