Complementary Angles Calculator

This calculator helps you find complementary angles. Two angles are complementary if their sum equals 90 degrees.

Input Parameters

Calculation Results

Calculation Formula

If angle1 + angle2 = 90°, then they are complementary

Where:
angle1 = First angle in degrees
angle2 = Second angle in degrees

Is Complementary?

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Complementary Angles Calculator Usage Guide

Learn how to use the Complementary Angles Calculator and understand complementary angles

What are Complementary Angles?

Complementary angles are two angles whose measures add up to 90 degrees. For example, a 30° angle and a 60° angle are complementary because 30° + 60° = 90°.

How to Use This Calculator

  1. Enter either the first angle or the second angle in degrees. You can leave one angle blank and the calculator will find the missing angle.
  2. Click the "Calculate" button to see if the angles are complementary and to find the missing angle if necessary.
  3. The calculator will display whether the angles are complementary and show the value of the missing angle if one was entered.

Examples

  • If you know an angle is 25°, enter 25 in the first field. The calculator will show that the complementary angle is 65°.
  • If you know an angle is 48°, enter 48 in the second field. The calculator will show that the complementary angle is 42°.
  • If you enter two angles that add up to 90° (like 45° and 45°), the calculator will confirm they are complementary.

Formula

Complementary Angles Formula:

angle₁ + angle₂ = 90°

This means if you know one angle, you can always find its complementary angle by subtracting it from 90°.