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

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## Area of a Circle

The area of a circle is defined as the amount of space it takes to completely 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). The formula can be rearranged to find the radius of a circle if you know its area. Area of a circle = π times the square of the radius.

## Area of a Circle formula

Given the radius of the circle, the area is the radius squared times pi. Given pi is 3.14159, it would be written as area=r2*pi

◉ Area of a circle with radius.

Area of circle = π(r)² = π(radius)²

◉ Area of a circle calculator with a diameter

Area of circle = π(D/2)² = π(dimater/2)²

◉ Area of a circle with a circumference

Area of circle = C²/4π = circumference²/4π

## How to solve the area of a circle

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

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

**Example.2:-The circumference of a circle is 20 cm, find its 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.

**Example.4:-Area of a 12-inch radius of a circle,**

**Answer:- **Area of a circle = π(radius)² = 22/7 * (12)² = 452.38934 inch².

## How to use the area of a circle calculator

Given a radius of a circle, the formula for finding its area is A = πr2. It is a powerful tool for calculating how much area a circle takes up. For example, a circle with a radius of 10 meters can be found by entering 10 for the radius value. By doing so, the area is calculated to be 314.16 square meters. If you don’t know the radius of a circle, there is a formula for that as well. If you know the diameter of the circle, just divide the diameter by two to obtain the radius. The formula for the area of a circle with diameter d is A = πd2/4 When using the above formula.