If the radius of a circle is 4 what is the area

The area of a circle calculator helps you compute the surface of a circle given a diameter or radius. Our tool works both ways - no matter if you're looking for an area to radius calculator or a radius to the area one, you've found the right place ◔

We'll give you a tour of the most essential pieces of information regarding the area of a circle, its diameter, and its radius. We'll learn how to find the area of a circle, talk about the area of a circle formula, and discuss the other branches of mathematics that use the very same equation.

So, let's see how to find the area of a circle. There are several ways to achieve it. Here, we can calculate the area of a circle using a diameter or using a radius.

You can find the diameter of a circle by multiplying the radius of a circle by two:

Diameter = 2 * Radius

Area of a circle radius. The radius of a circle calculator uses the following area of a circle formula:

Area of a circle = π * r2

Area of a circle diameter. The diameter of a circle calculator uses the following equation:

Area of a circle = π * (d/2)2

Where:

• π is approximately equal to 3.14. It doesn't matter whether you want to find the area of a circle using diameter or radius - you'll need to use this constant in almost every case.

🔎 Another relevant aspect of circles is their circumference. You can learn more about it and its relationship with area in our circle formula calculator

Now that you know how to calculate the area of a circle, we encourage you to try our other circle calculators:

A sector of a circle is section of a circle between two radii. You can think of it as a giant slice of pizza.

It's a "cut-off" part of a circle, limited by a chord or a secant.

It's an angle with the vertex in the center, whose arms extend to the circumference.

You can easily calculate everything, the area of a circle, its diameter, and its radius, using our area of a circle calculator in a blink of an eye:

1. Determine whether your given value is a diameter or a radius using the picture on the right and definitions available in the section above (you can calculate the area of a circle using its diameter as well as radius).

2. Enter your value into the proper field of the calculator.

3. It didn't take long - your results are here! We decided to include the step-by-step solution and all the most important data right below the calculator.

That is how to calculate the area of a circle in no time 😉.

The circle's area found with both the radius and diameter calculators serves as a base for many other equations - not only in mathematics but also in everyday life! Here are a few examples where knowing how to find the area of a circle might be useful:

• We need to know the surface area of a circle in order to calculate a cone's volume and its surface area 🎉

• Your pizza party wouldn't be complete without our pizza tool based on the diameter to area calculator 🍕

• We use calculations similar to this one when obtaining information about a sphere, such as sphere volume.🌐

• Do you fancy nice dresses? Maybe you love to sew? Discover our circle skirt calculator! Efficient sewing has never been easier. 👗

Here is the answer to questions like: how to find the area of a circle with radius 4 inches?

Circle Calculator

Use the this circle area calculator below to find the area of a circle given its radius, or other parameters. To calculate the area, you just need to enter a positive numeric value in one of the 3 fields of the calculator. You can also see at the bottom of the calculator, the step-by-step solution.

Here a three ways to find the area of a circle (formulas):

See below some definitions related to the formulas:

Circumference

Circumference is the linear distance around the circle edge.

Radius

The radius of a circle is any of the line segments from its center to its perimeter. The radius is half the diameter or r = d2.

Diameter

The diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. The diameter is twice the radius or d = 2·r.

The Greek letter π

π represents the number Pi which is defined as the ratio of the circumference of a circle to its diameter or π = Cd . For simplicity, you can use Pi = 3.14 or Pi = 3.1415. Pi is an irrational number. The first 100 digits of Pi are: 3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 ...

Note:

If you input the radius in centimeters, you will get the answer in square centimeters (cm²), if in inches, will get the answer in square inches (in²) and so on ...

Circumference is often misspelled as circunference.

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