To work out the area of a circle: Find the value of the radius. If the diameter is given, this must be halved. Substitute the value of the radius into the formula for the area of a circle.

Finding the area of a circle is easy with pizza and infinity. One of the oldest calculus problems, finding the area of a circle, can be visualized using a pizza. By dividing it up into ever ...

Letter Published: 02 April 1914 A Triangle that gives the Area and Circumference of any Circle, and the Diameter of a Circle equal in Area to any given Square G. B. MATHEWS Nature 93, 110 (1914 ...