With this calculator you can easily know the area of a circle or circumference from several variables, such as: Radius, Diameter or Length of the circumference.
In addition to the calculator you will find 3 different ways to calculate the area of a circle and many practical examples.
Formulas to calculate the area of a circle:
1. Formula to calculate area of a circle from the radius: To make this calculation you must have the radius of the circle and with the following formula:
Where:
- A: Area of the circle
- π: Constant Number equivalent to 3.1415
- A: Circle radius
2. How to calculate the area of a circle when you have the diameter: For this calculation you must have the diameter of the circle and then enter it in the following formula:
Where:
- A: Area of the circle
- π: Constant Number equivalent to 3.1415
- D: Diameter of the circle
3. Finally, there is the formula for calculation of Area from the length of the circumference: This formula facilitates the calculation of the area when you count with the length of the circumference.
Where:
- AR: Circle radio
- π: Constant Number equivalent to 3.1415
- LC: Length of the circumference.
Examples of use for formulas for calculating the area:
Example 1: A pizza has a radius of 20cm. What is the area of the pizza?
Solution:
We take the formula from radio to area and replace the value of the radius in the following way: A = πx20cm ^ 2, the result will be: 31,83cm ^ 2
Example 2: The rim of a Mazda 2 car has a diameter of 16 “. What is the area of this tire?
From the formula of diameter to area, we can replace the diameter in this formula, being as follows: A = (πx16 “^ 2) / 4, the result will be: 20.37” ^ 2
Example 3: The pipe of an aqueduct has a circumference length of 34cm. What will be the area of the pipe?
To calculate the area you must enter the value of the circumference length in the corresponding formula, as I show below: A = (34cm ^ 2) / πx4, the result will be: 91,99cm ^ 2