I know the Elipise tool ShiftDrag for a perfect circle selection but not how to type in an exact diameter is there a function for this in CS4. Area of a Circle Calculator. Pi r2 where rradius.
Because 2 x r is the same as the diameter you also can write the formula as C p x d.
For example if the length of the circumference of the circle is 157 in divide that by 314 Pi and you get 5. If you dont have the radius or the circumference divide the area of the circle by p and then find that numbers square root to get the radius. I know the Elipise tool ShiftDrag for a perfect circle selection but not how to type in an exact diameter is there a function for this in CS4. O Circle diameter.