circumference is the distance around the circle, so it sounds as though you are stating the circumference in your original question; 66 inches.
207
12
66 = 198
66 squared equals 4,356.
If 150 / x = 66, then x = 2.2727 cmSuppose the length is L cm.Then 150*L cm = 66 cmSo L cm = 66 cm/150 = 66/150 cm = 0.44 cm = 4.4 mm.
53
The circumference of a 21-inch circle is: 66 inches.(C = d x Pi).
66 feet
Divide your circumference by pi. Diameter is 66 / 3.141592654 = 21 inches.
The circumference of a circle with a 21 mile diameter is 66 miles (approx).
132 pi
The radius is 10.5
21 inches
Circumference = 3.14 x diameter Diameter = radius x 2 So...... 3.14 x 132 = 414.48
By a 21-inch circle I presume you mean that the diameter is 21 inches. So the radius is half as long, 10.5 inches. The formula for the circumference of a circle is 2 pi r, where r is the radius. Pi is about 3.14. That is accurate to 2 decimals, or 3 significant digits all together. I use that approximation because the dimension we are given has 2 significant digits. So the circumference is pi times the diameter; we multiply 3.14 by 21 inches and get 65.94. To 2 significant digits, that is 66 inches. If you meant that the radius was 21 inches, then the circumference would be twice as much, or 132 inches.
Circumference = Pi X Diameter; Pi (3.141590) x 66 = 207.3 In.
66%
Area of circle: pi*2.75 squared = 23.758 square feet to three decimal places