Area of a cirlce   =   π   ×   r²

The space occupied by a circle in 2-dimensional space is the area of a circle. For derivation of the formula see the section below.

Use this area calculator for more formulas and ready answers.

Trace a circular shape on paper and cut it along the edge. Fold it in half, then fold it 3 more times so you have 16 folding lines meeting at the centre like below.

Cut the circle along the folding lines to get 16 slices (sectors) and arrange them as below.

The circle is roughly arranged into a rectangle so their areas are now the same.

Area of the circle = Area of the rectangle
= Length × Breadth
= π × Radius × Radius

Area  = 

22

17

 ×  49⁷ × 49
=  7546 m²

Diameter  =  24 cm
Radius  =  24 ÷ 2
=  12 cm
Area  =  π × 12 × 12
=  144 π cm²

Radius  =  5 cm ÷ 2
=  2.5 cm

Area of a semicircle  =  Half of the area of the circle
=  

1

2

× 3.14 × 2.5 × 2.5
=  9.81 cm²

Area of a quadrant  =  A quarter of the area of the circle
=  

1

24

 × 

1122

17

 × 7¹ × 7
=  38.5 m²

Area of the middle circle  =  3.14 × 6 × 6
=  113.04 cm²
4 quadrants of radius 12 cm together make 1 circle of radius 12 cm.

Area of 4 quadrants  =  Area of 1 circle
=  3.14 × 12 × 12
=  452.16 cm²

Area of fan  =  113.04 + 452.16
=  565.2 cm²