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Last updated on June 25th, 2025

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Complementary Angle 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 complementary angle calculators.

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What is a Complementary Angle Calculator?

A complementary angle calculator is a tool to find the complementary angle of a given angle. Since complementary angles add up to 90 degrees, this calculator helps determine the unknown angle when one angle is known.

This calculator makes the process much easier and faster, saving time and effort.

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How to Use the Complementary Angle Calculator?

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

 

Step 1: Enter the known angle: Input the angle into the given field.

Step 2: Click on calculate: Click on the calculate button to find the complementary angle.

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

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How to Calculate Complementary Angles?

To calculate complementary angles, there is a simple formula that the calculator uses. Complementary angles add up to 90 degrees. Therefore, if you have one angle, you can find the other using:

Complementary Angle = 90° Known Angle

So why are we subtracting the known angle from 90? We are subtracting it to find the missing part that adds up to 90 degrees.

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Tips and Tricks for Using the Complementary Angle Calculator

When we use a complementary angle calculator, there are a few tips and tricks that we can use to make it a bit easier and avoid silly mistakes:

 

  • Think of real-world scenarios involving right angles to better understand.
     
  • Remember that complementary angles must always add up to 90 degrees.
     
  • Use precision in measurements to ensure accurate results.
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Common Mistakes and How to Avoid Them When Using the Complementary Angle Calculator

We may think that when using a calculator, mistakes will not happen. But it is possible for children to make mistakes when using a calculator.

Mistake 1

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Rounding too early before completing the calculation.

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Wait until the very end for a more accurate result.

For example, rounding too early can lead to incorrect complementary angle results. Always complete the calculation before rounding.

Mistake 2

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Forgetting that angles must total 90 degrees

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Ensure the total of both angles is exactly 90 degrees. If not, reassess your input and calculations.

Mistake 3

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Incorrectly interpreting angles larger than 90 degrees

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Complementary angles cannot be greater than 90 degrees. If your calculation suggests otherwise, recheck the input or the method used.

Mistake 4

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Relying on the calculator a bit too much for precision

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When we use the calculators, we need to keep in mind that the result we get is an approximation and needs to be adjusted accordingly for real-life situations. Always verify with manual calculations if necessary.

Mistake 5

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Assuming all calculators will handle all scenarios.

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We cannot expect calculators to handle irregular angle scenarios perfectly. Always check if the calculator is designed for specific angle types, especially in trigonometry.

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Complementary Angle Calculator Examples

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Problem 1

What is the complementary angle of 35 degrees?

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Use the formula: Complementary Angle = 90° - Known Angle

Complementary Angle = 90° - 35° = 55°

Therefore, the complementary angle of 35 degrees is 55 degrees.

Explanation

By subtracting 35 degrees from 90 degrees, we find that the complementary angle is 55 degrees.

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Problem 2

You have an angle of 60 degrees. What is its complementary angle?

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Use the formula: Complementary Angle = 90° - Known Angle

Complementary Angle = 90° - 60° = 30°

Therefore, the complementary angle of 60 degrees is 30 degrees.

Explanation

Subtracting 60 degrees from 90 degrees gives us the complementary angle of 30 degrees.

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Problem 3

A triangle has one angle measuring 20 degrees. Find its complementary angle.

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Use the formula: Complementary Angle = 90° - Known Angle

Complementary Angle = 90° - 20° = 70°

Therefore, the complementary angle of 20 degrees is 70 degrees.

Explanation

Subtracting 20 degrees from 90 degrees, we find that the complementary angle is 70 degrees.

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Problem 4

What is the complementary angle of 75 degrees?

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Use the formula: Complementary Angle = 90° - Known Angle

Complementary Angle = 90° - 75° = 15°

Therefore, the complementary angle of 75 degrees is 15 degrees.

Explanation

Subtracting 75 degrees from 90 degrees gives us the complementary angle of 15 degrees.

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Problem 5

How do you find the complementary angle of 50 degrees?

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Use the formula: Complementary Angle = 90° - Known Angle

Complementary Angle = 90° - 50° = 40°

Therefore, the complementary angle of 50 degrees is 40 degrees.

Explanation

By subtracting 50 degrees from 90 degrees, we find that the complementary angle is 40 degrees.

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FAQs on Using the Complementary Angle Calculator

1.How do you calculate complementary angles?

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2.What are complementary angles?

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3.Why is it important to know complementary angles?

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4.How do I use a complementary angle calculator?

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5.Is the complementary angle calculator accurate?

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Glossary of Terms for the Complementary Angle Calculator

  • Complementary Angle Calculator: A tool used to find the complementary angle when one angle is known.
     
  • Complementary Angles: Two angles that add up to 90 degrees.
     
  • Trigonometry: A branch of mathematics dealing with the relationships between the angles and sides of triangles.
     
  • Rounding: Adjusting a number to its nearest whole number or another specified increment.
     
  • Precision: The degree of exactness or refinement in a measurement or calculation.
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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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