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Last updated on September 11, 2025

Chord Length 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 chord length calculators.

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What is a Chord Length Calculator?

A chord length calculator is a tool used to determine the length of a chord given certain parameters of a circle.

Since the chord is a line segment with both endpoints on the circle, calculating its length can be complex depending on the information available.

This calculator simplifies the process, providing accurate and quick results.

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How to Use the Chord Length Calculator?

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

 

Step 1: Enter the circle's radius and the central angle (in degrees): Input these values into the given fields.

Step 2: Click on calculate: Click on the calculate button to compute the chord length.

Step 3: View the result: The calculator will display the chord length instantly.

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How to Calculate Chord Length?

To calculate the chord length, the calculator uses a simple formula.

For a circle with radius  r and a central angle (θ ) in degrees, the chord length c  is given by:  c = 2rsin(θ/2)

This formula uses the sine function to determine the length of the chord based on the segment of the circle.

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Tips and Tricks for Using the Chord Length Calculator

When using a chord length calculator, there are a few tips and tricks to ensure accuracy:

Consider using radians for more precise angle measurements in some contexts.

Double-check the radius and angle inputs for potential errors.

Use the calculator for real-world applications like construction or design projects where precise measurements are crucial.

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Common Mistakes and How to Avoid Them When Using the Chord Length Calculator

Even when using a calculator, mistakes can happen. Here are some common errors to watch out for:

Mistake 1

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Incorrect angle measurement units.

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Ensure you are using degrees if the calculator requires it, or convert to radians if necessary. Mixing up the units can lead to incorrect results.

Mistake 2

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Forgetting to halve the angle.

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The formula uses half the central angle, so failing to divide the angle by two will result in an incorrect chord length.

Mistake 3

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Incorrect input of radius or angle.

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A common mistake is entering the wrong values for the radius or angle. Double-check these values before calculation.

Mistake 4

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Relying too heavily on default values.

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Always verify that the default values in the calculator match the specifics of your problem. Adjust them as necessary to suit your needs.

Mistake 5

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Assuming all calculators are the same.

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Different calculators may have different features or require different inputs. Be sure to understand the specifics of the calculator you are using.

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Chord Length Calculator Examples

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Problem 1

What is the chord length of a circle with a radius of 10 cm and a central angle of 60 degrees?

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Use the formula:  c =2rsin(θ/2)

c = 2 × 10 × sin(60/2) 

c = 20 ×sin(30) 

Since sin(30) = 0., c = 20 × 0.5 = 10 

The chord length is 10 cm.

Explanation

By using a radius of 10 cm and a central angle of 60 degrees, the formula gives us a chord length of 10 cm.

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Problem 2

A circle has a radius of 15 meters and a central angle of 90 degrees. What is the chord length?

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Use the formula:  c = 2rsin(θ/2)

c = 2 ×15 × sin(90 / 2) 

c = 30 × sin(45) 

Since sin(45) = √2 / 2,

c = 30 × (√2 / 2) = 15√2

The chord length is approximately 21.21 meters.

Explanation

With a radius of 15 meters and a central angle of 90 degrees, the result is a chord length of approximately 21.21 meters.

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Problem 3

Find the chord length of a circle with a radius of 8 units and a central angle of 120 degrees.

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Use the formula: c =2rsin(θ/2)

 c = 2 × 8 × sin(120 / 2 )

 c = 16 ×sin(60) 

Since sin(60) = √(3 /2),

 c = 16 × √(3 / 2) = 8√3

The chord length is approximately 13.86 units.

Explanation

Using a radius of 8 units and a central angle of 120 degrees, we find the chord length to be approximately 13.86 units.

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Problem 4

A circle has a radius of 5 cm and a central angle of 150 degrees. Determine the chord length.

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Use the formula: c =2rsin(θ/2)

 c = 2 × 5 × sin(150/ 2)

 c = 10 × sin(75) 

Since sin(75) =(√6+√2) / 4 )

 c = 10 × ((√6+√2) / 4 )

The chord length is approximately 9.66 cm.

Explanation

With a radius of 5 cm and a central angle of 150 degrees, the chord length is approximately 9.66 cm.

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Problem 5

Calculate the chord length for a circle with a radius of 12 meters and a central angle of 45 degrees.

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Use the formula: c =2rsin(θ/2)

 c = 2 × 12 × sin(45/2) 

 c = 24 × sin(22.5) 

Since sin(22.5) ≈ 0.3827,

 c = 24 × 0.3827 ≈ 9.18  

The chord length is approximately 9.18 meters.

Explanation

For a radius of 12 meters and a central angle of 45 degrees, the chord length is approximately 9.18 meters.

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FAQs on Using the Chord Length Calculator

1.How do you calculate chord length?

Given the radius  r and central angle θ in degrees, the chord length c  can be calculated using the formula: c =2rsin(θ/2)

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2.Is a chord the same as a radius?

No, a chord is a line segment with both endpoints on the circle, while the radius is the distance from the center of the circle to any point on the circle.

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3.Can the chord length calculator handle radians?

Yes, some calculators can handle both degrees and radians. Convert the angle to the required unit if necessary.

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4.How do I use a chord length calculator?

Input the radius and central angle, then click calculate. The calculator will provide the chord length.

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5.Is the chord length calculator accurate?

The calculator provides an accurate result based on the input values and the sine function. Double-check inputs for precision.

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Glossary of Terms for the Chord Length Calculator

  • Chord: A line segment with both endpoints on the circle.

 

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

 

  • Central Angle: The angle subtended at the center by two radii.

 

  • Sine Function: A trigonometric function used in the chord length formula.

 

  • Radians: An alternative unit to degrees for measuring angles.
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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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: She has songs for each table which helps her to remember the tables

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