Area of a Circle Calculator

circle area diagram
Area of Circle:

The area of a circle calculator helps you to calculate the area of a circle with the diameter, radius and circumference of a circle.

Area of a Circle

The area of a circle is defined as the amount of space it takes to surround the circle. It is calculated by the equation A = πr2, where A is the area, r is the radius, and π is the constant pi (approximately 3.14159).

area of circle

Area of a Circle formula

The formula for the area of a circle is:

Based onArea of Circle
RadiusA = π(r)² = π(radius)²
DiameterA = π(D/2)² = π(dimater/2)²
CircumferenceA = C²/4π = circumference²/4π


Example.1:- The radius of a circle is 10 cm, find the area of a circle.

Answer:- Area = πr² = 22/7 * (10)² = 314.15 cm².

Example. 2 The circumference of a circle is 20 cm, find its circle area.

Answer:- Circumference of circle = 2πr = 20 cm

radius = 10/π

Area = πr² = π * (10/ π)² = 100/π = 31.83 cm².

Example.3:- The diameter of a circle is 20cm, find its area.

Answer:- diameter = radius/2 ⇨ radius = diameter/2 = 20/2 = 10 cm.

Area = πr² = π * (10)² = 314.15 cm².


What is the area based on diameter?

Divide the diameter by 2 to obtain the radius of the circle. Then, square the radius and multiply it by π to calculate the area.
Area = π(diamter/2)²
where, π (pi) = 3.14159.

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