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Last updated on September 2, 2025

Area Of Sector Calculator

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Calculators are reliable tools for solving simple mathematical problems and advanced calculations like trigonometry. Whether you’re cooking, tracking BMI, or planning a construction project, calculators will make your life easy. In this topic, we are going to talk about the area of sector calculators.

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What is an Area Of Sector Calculator?

An area of sector calculator is a tool to determine the area of a sector in a circle. A sector is a part of a circle bounded by two radii and the arc between them. This calculator makes the calculation much easier and faster, saving time and effort.

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How to Use the Area Of Sector Calculator?

Given below is a step-by-step process on how to use the calculator:

 

Step 1: Enter the radius: Input the radius of the circle into the given field.

Step 2: Enter the angle: Input the central angle of the sector in degrees.

Step 3: Click on calculate: Click on the calculate button to get the area of the sector.

Step 4: View the result: The calculator will display the result instantly.

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How to Calculate the Area of a Sector?

To calculate the area of a sector, there is a simple formula that the calculator uses.

The formula is: Area of Sector = (θ/360) × π × r² where θ is the central angle in degrees and r is the radius of the circle.

This formula takes a fraction of the circle's area (πr²) based on the angle θ, which represents the sector's portion of the full circle.

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Tips and Tricks for Using the Area Of Sector Calculator

When we use an area of sector calculator, there are a few tips and tricks that we can use to make it a bit easier and avoid silly mistakes: 

Ensure the angle is in degrees. If it's in radians, convert it to degrees first. 

Double-check your radius input; a mistake here can significantly affect the result. 

Remember that a sector's area is always part of the total circle's area.

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Common Mistakes and How to Avoid Them When Using the Area Of Sector Calculator

We may think that using a calculator prevents mistakes, but errors can still occur. Here are common mistakes and how to avoid them:

Mistake 1

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Entering the wrong angle measurement

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Ensure that the angle is entered in degrees, not radians or any other unit. A wrong unit will lead to incorrect calculations.

Mistake 2

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Misplacing the radius value

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A common error is inputting the wrong radius value. Always double-check that the radius corresponds to the correct circle.

Mistake 3

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Forgetting to use the π constant correctly

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Ensure that the calculator uses the accurate value of π (around 3.14159) for the calculation to get a precise result.

Mistake 4

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Relying solely on the calculator for complex scenarios

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While calculators are helpful, they may not consider specific conditions like sectors from concentric circles. Always verify results when dealing with non-standard problems.

Mistake 5

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Ignoring the units of measurement

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Make sure that all measurements are in the same unit system (e.g., all in centimeters or all in meters) to ensure consistency in the result.

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Area Of Sector Calculator Examples

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Problem 1

What is the area of a sector with a radius of 10 cm and a central angle of 45 degrees?

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Use the formula:

Area of Sector = (θ/360) × π × r²

Area of Sector = (45/360) × π × 10² ≈ 7.85 cm²

So, the area of the sector is approximately 7.85 cm².

Explanation

By substituting the values into the formula, we calculate the area of the sector as approximately 7.85 cm².

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Problem 2

Find the area of a sector with a 15-degree angle in a circle with a radius of 20 cm.

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Use the formula:

Area of Sector = (θ/360) × π × r²

Area of Sector = (15/360) × π × 20² ≈ 52.36 cm²

Therefore, the area is approximately 52.36 cm².

Explanation

The formula calculates the area by considering the 15-degree angle representing a fraction of the entire circle.

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Problem 3

Calculate the area of a sector with a radius of 8 meters and an angle of 90 degrees.

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Use the formula:

Area of Sector = (θ/360) × π × r²

Area of Sector = (90/360) × π × 8² ≈ 50.27 m²

Therefore, the area of the sector is approximately 50.27 m².

Explanation

The 90-degree angle is a quarter of the circle, so the area is a quarter of the circle's total area.

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Problem 4

Determine the area of a sector in a circle with a radius of 5 inches and a central angle of 120 degrees.

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Use the formula:

Area of Sector = (θ/360) × π × r²

Area of Sector = (120/360) × π × 5² ≈ 26.18 in²

Thus, the area of the sector is approximately 26.18 in².

Explanation

The 120-degree central angle covers one-third of the circle, so the area is one-third of the total.

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Problem 5

If a sector of a circle has a radius of 12 meters and a central angle of 200 degrees, what is its area?

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Use the formula:

Area of Sector = (θ/360) × π × r²

Area of Sector = (200/360) × π × 12² ≈ 251.33 m²

Hence, the area is approximately 251.33 m².

Explanation

The 200-degree angle accounts for more than half the circle, impacting the area proportionately.

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FAQs on Using the Area Of Sector Calculator

1.How do you calculate the area of a sector?

Divide the central angle by 360, then multiply by π and the radius squared to calculate the area.

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2.Is the area of a sector always less than the area of the circle?

Yes, the area of a sector is always a fraction of the circle's total area, based on the angle's proportion of 360 degrees.

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3.Why do we use the angle in degrees for the formula?

We use degrees because the formula is designed to divide the circle's total area (360 degrees) into proportional sectors.

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4.How do I use an area of sector calculator?

Simply input the radius and central angle, then click calculate. The calculator will show the result.

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5.Is the area of sector calculator accurate?

The calculator provides an accurate result based on the input values and the formula used, assuming standard conditions.

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Glossary of Terms for the Area Of Sector Calculator

  •  Sector: A portion of a circle bounded by two radii and the arc between them. 

 

  • Radius: The distance from the center of a circle to any point on its circumference. 

 

  • Central Angle: The angle formed at the center of the circle by two radii. 

 

  • π (Pi): A mathematical constant approximately equal to 3.14159, representing the ratio of a circle's circumference to its diameter. 

 

  • Degrees: A unit of measurement for angles, with a full circle encompassing 360 degrees.
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Seyed Ali Fathima S

About the Author

Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.

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Fun Fact

: She has songs for each table which helps her to remember the tables

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