The area of a circle with a 9cm radius is 254.34.

To calculate the area of a circle, you use the formula Area= Pi x r2, which is Pi times the radius (the length around the outside of the circle) squared. To calculate this you could get a calculator with a Pi button, these can be bought at any stationery store.

If the radius is 9cm, the calculation is Pi x 9 squared. Pi is 3.14, and so the equation looks like this: 3.14x9 squared. Nine squared is 81, so the calculation becomes 3.14 x 81, which works out at 254.34 cm squared.

To calculate the area of a circle, you use the formula Area= Pi x r2, which is Pi times the radius (the length around the outside of the circle) squared. To calculate this you could get a calculator with a Pi button, these can be bought at any stationery store.

If the radius is 9cm, the calculation is Pi x 9 squared. Pi is 3.14, and so the equation looks like this: 3.14x9 squared. Nine squared is 81, so the calculation becomes 3.14 x 81, which works out at 254.34 cm squared.