Circle Area
Enter the radius of the circle to calculate its area. Use a period as the decimal separator.
The area of the circle is:
What is a Circle?
A circle is a geometric figure whose points are all equidistant from a central point. The distance from this central point to the circle is called the radius.
How to Find the Area of a Circle
The area of a circle represents the number of square units inside it. To calculate the area, you must know its radius (r), the distance from the center of the circle to its circumference. You can also obtain the radius by dividing the diameter (d) by 2.
Formula to calculate the area of a circle:
Practical Example
Let's say we need to find the area of a circle, and we are given the length of its diameter, which for this example, we'll assign a value of 8 cm.
Step 1: Determine the radius (r)
If we already know the diameter (d) of the circle, then by dividing it by 2, we obtain the radius (r). For this example, then:
Radius = 8 ÷ 2
Radius = 4 cm
If the exercise statement provides you with the radius directly, you can skip this step and proceed directly to step 2.
Step 2: Substitute the radius in the area formula
From the previous step, we obtained the value of the radius = 4 cm. What remains is to replace this length in the formula to calculate the area of the circle.
Circle Area = π · 16
Circle Area = 50.26 cm²
That's it. We have calculated the area of a circle quickly and easily. Remember the relationship between the diameter and the radius when solving similar mathematical exercises.