The formula for the area of a circle is p x radius2 but the diameter of the circle is d 2 x r 2 so another way to write it is p x diameter 22. Remember that what you do to one. The radius is the length from the center of a circle to the edge of the circle.
Learn how to graph the equation of a circle by completing the square.
The radius of the circle is. Or when you know the Diameter. This variable is squared. A p r2.