Area of a circle

The area of a circle is the size of the region that the circle covers. Let the radius be r. Then the area of the circle, which we denote A, is

$A = π \cdot r^{2}$

The symbol π stands for pi. Its approximate value is 3.14, but we usually leave the answer as a multiple of pi. The circle below has radius r = 3, so its area is

$A = π \cdot 3^{2} = 9 π \approx 28.26$

Calculator: work out the area of a circle

Chapters: Area of a square, Area of a rectangle, Area of a circle, Sector of a circle, Area of a trapezium, Area of a parallelogram, Area of a rhombus, Area of a regular polygon, Surface area of a sphere, Surface area of a cube, Surface area of a cuboid, Surface area of a cylinder, Surface area of a cone, Surface area of a pyramid

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