The area of a circle with a radius of 56.5cms is approximately how many square metres?
Area of a circle Area of a circle In geometry, the area enclosed by a circle of radius is . Here the Greek letter represents a constant, approximately equal to 3.14159, which is equal to the ratio of the circumference of any circle to its diameter. One method of deriving this formula, which originated with Archimedes, involves viewing the circle as the limit of a sequence of regular polygons. The area of a regular polygon is half its perimeter multiplied by the distance from its center to its sides, and the corresponding formula (that the area is half the perimeter times the radius, i.e.
Area of a circle value of formula_72 at x. A spherical circle is the set of points a geodesic distance "R" from the zenith point z. Equivalently, with a fixed embedding into formula_73, the spherical circle of radius formula_74 centered at z is the set of x in formula_64 such that formula_76. We can also measure the area of the spherical disk enclosed within a spherical circle, using the intrinsic surface area measure on the sphere. The area of the disk of radius "R" is then given by More generally, if a sphere formula_78 has radius of curvature formula_79, then the area of the