We take value of radius from user and using above formula calculate area of the circle and output result to the console window. Pie is actually an infinite number but for the sake of convenience we consider the value of pie as 314. Now that you know the formulas and what they are used for lets work through some example problems.
To find the area using the diameter or the distance from one side of the circle to the other first divide the diameter in half to find the radius.
Learn more at Area of Plane Shapes. Find the area of triangles and quadrilaterals by first using the Pythagorean Theorem to find missing side lengths. Square feet can also be expressed as ft 2 or sq. Area by Counting Squares.